# Quiz 7: Conservation of Energy

Physics & Astronomy

Q 1Q 1

A woman runs up a flight of stairs. The gain in her gravitational potential energy is U. If she runs up the same stairs with twice the speed, what is her gain in potential energy?
A) U
B) 2U
C) U
D) 4U
E) U

Free

Multiple Choice

A

Q 2Q 2

Susana ascends a mountain via a short, steep trail. Sean ascends the same mountain via a long, gentle trail. Which of the following statements is true?
A) Susana gains more gravitational potential energy than Sean.
B) Susana gains less gravitational potential energy than Sean.
C) Susana gains the same gravitational potential energy as Sean.
D) To compare energies, we must know the height of the mountain.
E) To compare energies, we must know the lengths of the two trails.

Free

Multiple Choice

C

Q 3Q 3

The reference point for gravitational potential energy
A) must be at the initial position of the object.
B) must be at the final position of the object.
C) must be at ground level.
D) must be at the lowest position ever reached by the object.
E) can be chosen arbitrarily.

Free

Multiple Choice

E

Q 4Q 4

Which of the following statements is true?
A) The kinetic and potential energies of an object must always be positive quantities.
B) The kinetic and potential energies of an object must always be negative quantities.
C) Kinetic energy can be negative but potential energy cannot.
D) Potential energy can be negative but kinetic energy cannot.
E) None of these statements is true.

Free

Multiple Choice

Q 5Q 5

Which of the following statements is NOT correct?
A) The work done by a conservative force on an object is independent on the path taken.
B) The work done by a conservative force on an object along path AB is negative that of path BA.
C) The force due to gravity is an example of a conservative force.
D) Friction is an example of a conservative force.
E) The work done by friction on an object depends on the path taken.

Free

Multiple Choice

Q 6Q 6

Calculate the work done by a force, , around a closed path, first going from P

_{1}(1,1) to P_{2}(4,4) along path a and returning along path b. A) 0 J B) 3 J C) 7 J D) 13 J E) 17 JFree

Multiple Choice

Q 7Q 7

Calculate the work done by a force, , along the path (0,0) P

_{1}(2,0) P_{2}(2,2). A) 2 J B) 4 J C) 6 J D) 8 J E) 10 JFree

Multiple Choice

Q 8Q 8

A 75-kg man climbs the stairs to the fifth floor of a building, a total height of 16 m. His potential energy has increased by
A) 1.2 10

^{4}J B) 5.9 10^{4}J C) 4.7 10^{4}J D) 3.8 10^{4}J E) 5.9 10^{3}JFree

Multiple Choice

Q 9Q 9

A 5200-kg cable car in Hong Kong is pulled a distance of 360 m up a hill inclined at 12º from the horizontal. The change in the potential energy of the car is
A) 1.8 10

^{7}J B) 1.2 10^{7}J C) 3.8 10^{6}J D) 6.0 10^{7}J E) 1.8 10^{6}JFree

Multiple Choice

Q 10Q 10

A block with a mass M = 4.85 kg is resting on a slide that has a curved surface. There is no friction. The speed of the block after it has slid along the slide sufficiently far for its vertical drop to be 19.6 m is
A) 19.6 m/s
B) 384 m/s
C) 73 m/s
D) 43.2 m/s
E) The problem cannot be solved because the shape of the curved slide is not given.

Free

Multiple Choice

Q 11Q 11

A spring with force constant k = 300 N/m is compressed 9.0 cm. What is the potential energy in the spring?
A) 1.2 10

^{4}J B) 2.4 J C) 2.7 10^{4}J D) 27 J E) 1.2 JFree

Multiple Choice

Q 12Q 12

Which of the following statements is true?
A) Friction is a conservative force and does negative work.
B) Potential energy may be defined by the equation U(x) = -dF(x)/dx
C) The work done by a conservative force between two points depends on the path taken between those points.
D) A conservative force cannot change a body's total energy.
E) The work done by a conservative force while a body moves at constant velocity must be zero.

Free

Multiple Choice

Q 13Q 13

When the potential energy U(r) is given as in Figure A, then the force is given in Figure B by curve
A) 1
B) 2
C) 3
D) 4
E) 5

Free

Multiple Choice

Q 14Q 14

A block of mass m starts from position 1 and moves up a frictionless inclined plane with an initial speed v. At some later time the block has moved down the plane and at position 2 has a speed u. If a and b are the heights above the bottom of the plane, the magnitude of u can be determined from
A) u

^{2}= v^{2}- 2g(a - b) B) u^{2}= v^{2}+ 2g(a + b) C) u^{2}= v^{2}+ 2g(a - b) D) u^{2}= v^{2}+ 2g(b - a) E) u^{2}= v^{2}+ g(a - b)Free

Multiple Choice

Q 15Q 15

The graph shows a plot of the gravitational potential energy U of a 1-kg body as a function of its height h above the surface of a planet. The acceleration due to gravity at the surface of the planet is
A) 0 m/s

^{2 }B) 9.8 m/s^{2 }C) 6.0 m/s^{2 }D) 3.0 m/s^{2 }E) None of these is correct.Free

Multiple Choice

Q 16Q 16

According to Quantum Chromodynamics, the force that keeps quarks confined within a proton (or neutron) increases as the separation between the individual quarks increases. Which statement below best represents this scenario?
A) The quarks are tied together by nonstretchable strings.
B) The quarks are tied together by elastic strings.
C) The quarks move independently of each other.
D) The force between the quarks has a 1/r

^{2}behavior like gravity. E) The potential energy of a quark decreases with separation.Free

Multiple Choice

Q 17Q 17

In magazine car tests an important indicator of performance is the zero to 60 mph (0 to 96.6 km/h) acceleration time. A time below 6 s is considered to be extremely quick. If a car with mass 1300 kg were dropped vertically from a great height, how long would it take to go from zero to 60 mph and what would the magnitude of the change in gravitational potential energy be during this time? (neglect air resistance)
A) 2.74 s and 17.4 kJ
B) 2.74 s and 468 kJ
C) 2.74 s and 468 MJ
D) 0.37 s and 468 MJ
E) 2.74 s and 17.4 MJ

Free

Multiple Choice

Q 18Q 18

Which potential energy versus displacement curve best represents that of an extended spring?
A) 1
B) 2
C) 3
D) 4
E) 5

Free

Multiple Choice

Q 19Q 19

The potential energy function for a conservative force acting in the x direction on a particle is shown below. The number of points where the net force on the particle is equal to zero are
A) B and D.
B) C and E.
C) B, C, D, and E.
D) A and F.
E) any point between C and D.

Free

Multiple Choice

Q 20Q 20

The potential energy function for a conservative force acting in the x direction is shown in the figure on the right. Where would the particle experience a force directed to the right?
A) between A & B and E & F
B) between B & C and C & D
C) between B & C and D & E
D) at points B and D
E) at points C and E

Free

Multiple Choice

Q 21Q 21

The total mechanical energy of any system is
A) always the work done by gravity.
B) the difference between the kinetic and potential energy at any point.
C) the sum of the kinetic and potential energy at any point.
D) the sum of the translational and rotational kinetic energies at any point.
E) the potential energy of a spring at any displacement.

Free

Multiple Choice

Q 22Q 22

A body falls through the atmosphere (consider air resistance) gaining 20 J of kinetic energy. How much gravitational potential energy did it lose?
A) 20 J
B) more than 20 J
C) less than 20 J
D) It is impossible to tell without knowing the mass of the body.
E) It is impossible to tell without knowing how far the body falls.

Free

Multiple Choice

Q 23Q 23

A projectile of mass m is propelled from ground level with kinetic energy of 450 J. At the exact top of its trajectory, its kinetic energy is 250 J. To what height above the starting point does the projectile rise?
A) m
B) m
C) m
D) m
E) m

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Multiple Choice

Q 24Q 24

A block of mass, m, is pushed up against a spring, compressing it a distance x, and is then released. The spring projects the block along a frictionless horizontal surface, giving the block a speed v. The same spring projects a second block of mass 4m, giving it a speed 3v. What distance was the spring compressed in the second case?
A) x
B) 2x
C) 3x
D) 4x
E) 6x

Free

Multiple Choice

Q 25Q 25

You ride a roller coaster car of mass 1500 kg down a frictionless track a distance H = 23m above the bottom of a loop as shown. If the loop is 15 m in diameter, the downward force of the rails on your car when it is upside down at the top of the loop is
A) 4.6 10

^{4}N B) 3.1 10^{4}N C) 1.7 10^{4}N D) 0.98 kN E) 1.6 10^{3}NFree

Multiple Choice

Q 26Q 26

Release mass m on a string from rest at point A. As it passes the lowest point B, the tension in the string is
A) impossible to determine; the answer depends on the length of the string.
B) mg
C) 2mg
D) 3mg
E) None of these is correct.

Free

Multiple Choice

Q 27Q 27

A woman on a bicycle traveling at 10 m/s on a horizontal road stops pedaling as she starts up a hill inclined at 3.0º to the horizontal. If friction forces are ignored, how far up the hill does she travel before stopping?
A) 5.1 m
B) 30 m
C) 97 m
D) 10 m
E) The answer depends on the mass of the woman.

Free

Multiple Choice

Q 28Q 28

Two unequal masses hang from either end of a massless cord that passes over a frictionless pulley. Which of the following is true about the gravitational potential energy (U) and the kinetic energy of the system (K) after the masses are released from rest?
A) U < 0 and K > 0
B) U = 0 and K > 0
C) U < 0 and K = 0
D) U = 0 and K = 0
E) U > 0 and K < 0

Free

Multiple Choice

Q 29Q 29

A child is sitting on the seat of a swing with ropes 10 m long. Her father pulls the swing back until the ropes make a 37º angle with the vertical and then releases the swing. If air resistance is neglected, what is the speed of the child at the bottom of the arc of the swing when the ropes are vertical?
A) 11 m/s
B) 8.8 m/s
C) 14 m/s
D) 6.3 m/s
E) 12 m/s

Free

Multiple Choice

Q 30Q 30

Use the figure to the right for the next problems.
A flexible rope of mass m and length L = L

_{1}+ L_{2}, hangs over a frictionless peg, as shown in the figure. -What is the change in potential energy when the end of the rope just slides off the peg? A) mgL B) mgL_{1}C) mgL_{2}D) mgL_{1}^{2}/(L) E) mgL_{1}L_{2}/(L)Free

Multiple Choice

Q 31Q 31

Use the figure to the right for the next problems.
A flexible rope of mass m and length L = L

_{1}+ L_{2}, hangs over a frictionless peg, as shown in the figure. -What is the speed of the rope when it just slides off the peg? A) B) C) D) E)Free

Multiple Choice

Q 32Q 32

A simple pendulum has a bob of mass M. The bob is on a light string of length . The string is fixed at C. At position A, the string is horizontal and the bob is at rest. The bob is released from A and swings to B, where the string is vertical. The tension in the string when the bob first reaches B is
A)
B) 2Mg
C) Mg
D) Mg
E) None of these is correct.

Free

Multiple Choice

Q 33Q 33

A roller coaster starts from rest at point A. If you ignore friction and take the zero of potential energy to be at C,
A) the kinetic energy of the coaster at D will be equal to its potential energy at A.
B) the kinetic energy of the coaster at E will be equal to its potential energy at C.
C) the kinetic energy of the coaster at C will be equal to its potential energy at B.
D) the kinetic energy of the coaster at B will be equal to its potential energy at C.
E) None of these is correct.

Free

Multiple Choice

Q 34Q 34

A roller coaster starts from rest at point A. If you ignore friction and take the zero of potential energy to be at C,
A) the kinetic energy of the coaster at D will be equal to its potential energy at A.
B) the kinetic energy of the coaster at E will be equal to its potential energy at C.
C) the kinetic energy of the coaster at C will be equal to its potential energy at A.
D) the kinetic energy of the coaster at B will be equal to its potential energy at C.
E) None of these is correct.

Free

Multiple Choice

Q 35Q 35

The block shown in the figure is sliding on a frictionless surface. Its speed when it reaches the level portion of the surface on which it is sliding will be
A) 3.14 m/s
B) 7.67 m/s
C) 9.81 m/s
D) 13.3 m/s
E) None of these is correct.

Free

Multiple Choice

Q 36Q 36

The block shown in the figure is sliding on a frictionless surface. Its speed when it has traveled 9 m along the horizontal surface will be
A) 3.14 m/s
B) 7.67 m/s
C) 9.81 m/s
D) 13.3 m/s
E) None of these is correct.

Free

Multiple Choice

Q 37Q 37

Assuming the incline to be frictionless and the zero of gravitational potential energy to be at the elevation of the horizontal line,
A) the kinetic energy of the block just before it collides with the spring will be equal to mgh.
B) the kinetic energy of the block when it has fully compressed the spring will be equal to mgh.
C) the kinetic energy of the block when it has fully compressed the spring will be zero.
D) the kinetic energy of the block just before it collides with the spring will be kx

^{2}. E) None of the above statements will be true.Free

Multiple Choice

Q 38Q 38

Assuming the incline to be frictionless and the zero of gravitational potential energy to be at the elevation of the horizontal line,
A) the kinetic energy of the block just before it collides with the spring will be equal to mgh.
B) the kinetic energy of the block when it has fully compressed the spring will be equal to mgh.
C) the potential energy of the block when it has fully compressed the spring will be zero.
D) the energy stored in the spring plus the gravitational potential energy of the block when it has fully compressed the spring will be equal to mgh.
E) None of the above statements will be true.

Free

Multiple Choice

Q 39Q 39

A mass, m, slides down a frictionless incline and hits a spring with spring constant k. Find the spring compression when the acceleration of the mass is zero.
A) mg/k
B) mg cos /k
C) mg sin /k
D) mgh sin /(kx)
E) None of the above statements is correct.

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Multiple Choice

Q 40Q 40

The surface shown in the figure is frictionless. If the block is released from rest, it will compress the spring at the foot of the incline
A) 4.00 m
B) 3.24 m
C) 1.57m
D) 0.989 m
E) None of these is correct.

Free

Multiple Choice

Q 41Q 41

Use the figure to the right for the next problems.
An object of mass m = 200 g slides down a frictionless ramp from a height H = 60 cm. Near the bottom of the ramp, the path changes into an arc of a circle with radius r = 20 cm. The arc has coefficient of kinetic friction

_{k}= 0.4. The angle = 120 and points P_{1}and P_{2}which are the ends of the arc, are at the same height. -What is the speed of the object at point P_{1}? A) 1.1 m/s B) 2.5 m/s C) 3.1 m/s D) 3.4 m/s E) 4.1 m/sFree

Multiple Choice

Q 42Q 42

Use the figure to the right for the next problems.
An object of mass m = 200 g slides down a frictionless ramp from a height H = 60 cm. Near the bottom of the ramp, the path changes into an arc of a circle with radius r = 20 cm. The arc has coefficient of kinetic friction

_{k}= 0.4. The angle = 120 and points P_{1}and P_{2}which are the ends of the arc, are at the same height. -What is the kinetic energy of the object at point P_{2}? A) 0.27 J B) 0.71 J C) 0.98 J D) 1.25 J E) none of the aboveFree

Multiple Choice

Q 43Q 43

Use the figure to the right for the next problems.
An object of mass m = 200 g slides down a frictionless ramp from a height H = 60 cm. Near the bottom of the ramp, the path changes into an arc of a circle with radius r = 20 cm. The arc has coefficient of kinetic friction

_{k}= 0.4. The angle = 120 and points P_{1}and P_{2}which are the ends of the arc, are at the same height. -A 5-kg box is pushed 5 m up a plane that is inclined at 30º with the horizontal. The coefficient of kinetic friction between the box and the plane is 0.20. The change in potential energy of the box is approximately A) 12.5 J B) 34.2 J C) 123 J D) 345 J E) 403 JFree

Multiple Choice

Q 44Q 44

Use the figure to the right for the next problems.
An object of mass m = 200 g slides down a frictionless ramp from a height H = 60 cm. Near the bottom of the ramp, the path changes into an arc of a circle with radius r = 20 cm. The arc has coefficient of kinetic friction

_{k}= 0.4. The angle = 120 and points P_{1}and P_{2}which are the ends of the arc, are at the same height. -The work done by a conservative force between two points is A) always positive. B) always dependent upon the time. C) always independent of the path. D) zero. E) never completely recoverable.Free

Multiple Choice

Q 45Q 45

Consider a motion in which a particle goes from A B along path 1 and from B back to A along path 2, as shown. W(AB, 1) = work in going from A B along path 1.
W(BA, 2) = work in going from B A along path 2.
If only conservative forces are acting, then
A) W(AB, 1) > W(BA, 2)
B) W(AB, 1) < W(BA, 2)
C) W(AB, 1) + W(BA, 2) > 0
D) W(AB, 1) + W(BA, 2) < 0
E) W(AB, 1) + W(BA, 2) = 0

Free

Multiple Choice

Q 46Q 46

A 4.0-kg block starts from rest and slides 5.0 m down a plane inclined at 60º to the horizontal. The coefficient of kinetic friction between the surface and the block is 0.20. The work done by friction on the block is
A) 98.0 J
B) 19.6 J
C) 3.92 J
D) 3.40 J
E) 64.0 J

Free

Multiple Choice

Q 47Q 47

A 10-kg box is at the top of a 5-m plane inclined at 37º with the horizontal. The box starts from rest and slides down the plane. The coefficient of kinetic friction is 0.20. The magnitude of the change in the potential energy of the box is
A) 30 kJ
B) 0.10 kJ
C) 0.29 kJ
D) 0.46 kJ
E) 0.39 kJ

Free

Multiple Choice

Q 48Q 48

A 10-kg box is pushed up a plane inclined at 37º with the horizontal. The box starts from rest and is pushed 5 m along the incline with a uniform acceleration of 2 m/s

^{2}. The coefficient of kinetic friction is 0.20 and the pushing force is parallel to the plane. The increase in the potential energy of the box is A) 0.10 kJ B) 0.29 kJ C) 0.36 kJ D) 0.46 kJ E) 0.39 kJFree

Multiple Choice

Q 49Q 49

You drive a golf ball from A and it travels to B. The weight of the ball is w. The decrease in its potential energy is given by
A) (r + t)w
B) (a + s + t)w
C) (a + b)w
D) (a + b + c)w
E) None of these is correct.

Free

Multiple Choice

Q 50Q 50

A system comprising two blocks is shown, one of which is on an inclined plane. The pulley is of negligible mass and is frictionless. The system starts from rest at position 1 and accelerates. Measurements taken when the blocks reach position 2 indicate that
(1)the kinetic energy of block A has changed by 330 J;
(2)the potential energy of block A has changed by 588 J;
(3)the kinetic energy of block B has changed by 110 J; and
(4)the potential energy of block B has changed by 98 J.
The amount of mechanical energy that has been converted to heat because of friction is
A) 12 J
B) 50 J
C) 258 J
D) 478 J
E) 710 J

Free

Multiple Choice

Q 51Q 51

A 3-kg block sits on an incline where the top half of the incline has a coefficient of kinetic friction of 0.5 and the bottom half is frictionless. The angle of inclination is 35 degrees. If the block is released and travels 10 m along the rough part of the incline and then 10 m along the smooth part before it makes contact with the spring (k = 200 N/m), calculate the distance the spring is compressed.
A) 1.47 m
B) 1.56 m
C) 2.16 m
D) 2.43 m
E) 1.39 m

Free

Multiple Choice

Q 52Q 52

A 5-kg mass with initial velocity 20 m/s slides along a frictionless horizontal surface then up a frictionless ramp (2 m long and at an angle 30 degrees to the horizontal) and onto a second horizontal surface. The block slides over a rough surface 15 m in length (

_{k}= 0.4) before moving again on a frictionless surface and then impacting upon an uncompressed spring. If the block compresses the spring a distance 2 m, what is the spring constant k for the spring? A) 304 N/m B) 451 N/m C) 84.0 N/m D) 32.8 N/m E) 353 N/mFree

Multiple Choice

Q 53Q 53

A hanging block A (m

_{A}= 15 kg) is connected by a light cable and a pulley wheel to a second block B (m_{B}= 10 kg) situated at the bottom of a frictionless inclined plane with angle 30 to the horizontal. If the hanging block is released from rest 5 m above the ground, find the maximum distance that block B travels up along the inclined plane. A) 9.0 m B) 4.0 m C) 2.3 m D) 7.3 m E) 6.5 mFree

Multiple Choice

Q 54Q 54

A 5-kg blob of putty is dropped from a height of 10.0 m above the ground onto a light vertical spring the top of which is 5 m above the ground. If the spring constant k = 200 N/m and the blob compresses the spring by 1.50 m, then find the amount of energy lost in sound and thermal energy.
A) 20.0 J
B) 169 J
C) 266 J
D) 438 J
E) 94.0 J

Free

Multiple Choice

Q 55Q 55

A mass m is released from a height 80 cm from the right-hand side of the track shown in the diagram at right. There is only friction acting along the horizontal portion 30 cm either side of the midpoint O with a kinetic coefficient of friction of

_{k}= 0.4. Determine (i) how many times does the mass m pass through the midpoint O, and (ii) how far from the midpoint does it come to rest. A) 6, .1 m B) 6, .2 m C) 3, .2 m D) 3, .1 m E) 1, 2 cmFree

Multiple Choice

Q 56Q 56

A mass m is released from a height 60 cm from the right-hand side of the track shown in the diagram at right. There is only friction acting on the mass on the horizontal portion 35 cm either side of the midpoint O, with a kinetic coefficient of friction of

_{k}= 0.5. Determine what is the velocity of the block the first time it passes through the midpoint, and on which side of the midpoint does it stop? A) 3.4 m/s, R B) 3.9 m/s, R C) 3.9 m/s, L D) 2.9 m/s, L E) 2.9 m/s, RFree

Multiple Choice

Q 57Q 57

A mass m is released from a height 75 cm from the right-hand side of the track shown in the diagram at right. There is only friction acting on mass along the horizontal portion 30 cm either side of the midpoint O, with a kinetic coefficient of friction of

_{k}= 0.4. Determine how high it reaches the second time it passes over to the left side, and in which direction is it moving when it stops? A) 27 cm, R B) 3.0 cm, R C) 27 cm, L D) 3.0 cm, L E) 51 cm, RFree

Multiple Choice

Q 58Q 58

Use the figure to the right to answer the next problems.
An object of mass m = 100 g slides down without rolling a rough incline from a height H = 60 cm. At
h = 30 cm, the object flies off the incline. The coefficient of kinetic friction is 0.4, and the angle = 30.
-What is the speed of the object just after it leaves the ramp?
A) 2.40 m/s
B) 1.34 m/s
C) 0.77 m/s
D) 0.54 m/s
E) None of these is correct.

Free

Multiple Choice

Q 59Q 59

Use the figure to the right to answer the next problems.
An object of mass m = 100 g slides down without rolling a rough incline from a height H = 60 cm. At
h = 30 cm, the object flies off the incline. The coefficient of kinetic friction is 0.4, and the angle = 30.
-How far from the base of the elevated incline does the object hit the floor?
A) 14.8 cm
B) 17.5 cm
C) 21.9 cm
D) 24.6 cm
E) None of these is correct.

Free

Multiple Choice

Q 60Q 60

Use the figure to the right to answer the next problems.
An object of mass m = 100 g slides down without rolling a rough incline from a height H = 60 cm. At
h = 30 cm, the object flies off the incline. The coefficient of kinetic friction is 0.4, and the angle = 30.
-According to the mass-energy relationship, how much energy is released if 1 kg of matter were converted to energy?
A) 1 J
B) 9 J
C) 3 10

^{8}J D) 3 10^{16}J E) 9 10^{16}JFree

Multiple Choice

Q 61Q 61

Use the figure to the right to answer the next problems.
An object of mass m = 100 g slides down without rolling a rough incline from a height H = 60 cm. At
h = 30 cm, the object flies off the incline. The coefficient of kinetic friction is 0.4, and the angle = 30.
-The minimum amount of energy released in an electron-positron annihilation is
A) 0
B) 0.511 MeV
C) 1.022 MeV
D) 2.044 MeV
E) None of these is correct.

Free

Multiple Choice

Q 62Q 62

By what fraction does your mass increase when you and your car travel down the highway at 70 mph? Assume that the total mass of your car and occupant is 2000 kg.
A) 5.38 10

^{ }^{15}B) 1.08 10^{ }^{11}C) 3.23 10^{ }^{6}D) 9.68 10^{5}E) None of these is correct.Free

Multiple Choice

Q 63Q 63

If you drive at the posted speed limit of 70 mph on the interstate, what is the fraction of your speed compared to the speed of light?
A) 6.48 10

^{ }^{8}B) 1.04 10^{ }^{7}C) 2.33 10^{ }^{7}D) 3.73 10^{ }^{7}E) None of these is correct.Free

Multiple Choice

Q 64Q 64

An electron has a rest mass of 0.511 MeV. From this information one can conclude that the rest mass of an electron is
A) 9.08 10

^{ }^{31}kg B) 8.82 10^{ }^{14}kg C) 2.94 10^{ }^{22}kg D) 5.68 10^{ }^{12}kg E) None of these is correct.Free

Multiple Choice

Q 65Q 65

The rest mass of an electron is 9.11 10

^{-31}kg. From this information one can conclude that the rest energy of an electron is A) 8.20 10^{ }^{14}MeV B) 0.512 MeV C) 2.73 10^{ }^{22}J D) 0.00171 MeV E) 0.171 MeVFree

Multiple Choice

Q 66Q 66

A proton has a rest mass of 938 MeV. From this information one can conclude that the rest mass of a proton is
A) 5.00 10

^{ }^{19}kg B) 1.50 10^{ }^{10}kg C) 1.67 10^{ }^{27}kg D) 1.04 10^{ }^{8}kg E) 2.34 10^{ }^{29}kgFree

Multiple Choice

Q 67Q 67

The rest mass of a proton is 1.67 10

^{-27}kg. From this information one can conclude that the rest energy of a proton is A) 1.50 10^{ }^{10}MeV B) 3.13 MeV C) 847 MeV D) 939 MeV E) 742 MeVFree

Multiple Choice

Q 68Q 68

Which of the following are units of mass?
A) MeV
B) MeV·c

^{2 }C) c^{2}/MeV D) 1/MeV E) MeV/c^{2 }Free

Multiple Choice

Q 69Q 69

Which of the following are units of energy?
A) MeV
B) MeV·c

^{2 }C) c^{2}/MeV D) 1/MeV E) MeV/c^{2 }Free

Multiple Choice

Q 70Q 70

The binding energy of a deuteron is 2.22 MeV. This means that
A) deuterons can be broken up by bombarding them with electromagnetic radiation possessing energy of at least 2.22 MeV.
B) deuterons can be broken up by bombarding them with particles possessing energy of at least 2.22 MeV.
C) if the deuterons are bombarded with particles whose energy exeeds 2.22 MeV, the excess energy appears as kinetic energy of the outgoing particles.
D) if the deuterons are bombarded with particles whose energy is less than 2.22 MeV, they will not be decomposed into their constituent parts.
E) all of these are correct.

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Multiple Choice

Q 71Q 71

Newtonian mechanics, compared to Einstein's Special Relativity is valid if
A) an object is traveling at a constant velocity.
B) an object has a very small mass.
C) the kinetic energy of an object is much less than its rest mass.
D) an object is not traveling at the speed of light.
E) the kinetic energy of an object is much greater than its rest mass.

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Multiple Choice

Q 72Q 72

When an electron in a hydrogen atom jumps from n = 2 to n = 1, the photon emitted is of frequency f = 4.572 10

^{14}Hz. What is the energy of the photon? A) 2.187 10^{ }^{15}J B) 3.029 10^{ }^{1}^{9}J C) 3.33 10^{ }^{9}J D) 6.623 10^{ }^{34}J E) None of these is correct.Free

Multiple Choice

Q 73Q 73

When a hydrogen atom absorbs a photon with E = 4.089 10

^{ }^{19}J, what is the frequency of the photon? A) 6.17 10^{1}^{4}Hz B) 2.45 10^{1}^{8}Hz C) 2.55 10^{8}Hz D) 6.623 10^{34}Hz E) None of these is correct.Free

Multiple Choice