Question 1

A racquetball strikes a wall with a speed of 30 m/s and rebounds in the opposite direction with a speed of 26 m/s.The collision takes 20 ms.What is the average acceleration of the ball during the collision with the wall? A)0 m/s² B)200 m/s² C)2800 m/s² D)1500 m/s² E)1300 m/s²

Accepted Answer

The average acceleration is calculated using the formula $a = \frac{\Delta v}{\Delta t}$, where $\Delta v$ is the change in velocity and $\Delta t$ is the time interval. The change in velocity is $26 m/s + 30 m/s = 56 m/s$ (since the ball reverses direction, we add the speeds). The time interval is $20 ms = 0.02 s$. Thus, $a = \frac{56 m/s}{0.02 s} = 2800 m/s^2$.

Question 2

A water rocket can reach a speed of 75 m/s in 0.050 seconds from launch.What is its average acceleration?

Accepted Answer

The answer of A water rocket can reach a speed...

Question 3

The captain orders his starship to accelerate from rest at a rate of "1 g" (1 g = 9.8 m/s²).How many days does it take the starship to reach 10% the speed of light? (Light travels at 3.0 × 10⁸ m/s.)

Accepted Answer

The answer of The captain orders his starship to accelerate...

Question 4

A runner runs around a track consisting of two parallel lines 96 m long connected at the ends by two semicircles with a radius of 49 m.She completes one lap in 100 seconds.What is her average velocity?
A)2.5 m/s
B)5.0 m/s
C)10 m/s
D)0 m/s
E)1.3 m/s

Accepted Answer

The average velocity of an object is calculated by dividing the total displacement by the total time taken. Since the runner starts and finishes at the same point, her total displacement is zero. Therefore, her average velocity is 0 m/s, regardless of the distance covered or the time taken.

Question 5

An airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h north for 750 miles.What is the average speed for the trip?
A)260 mi/h
B)270 mi/h
C)275 mi/h
D)280 mi/h

Accepted Answer

The total distance traveled is $2 \times 300 + 750 = 1350$ miles. The total time is $2 + \frac{750}{250} = 5$ hours. The average speed is $\frac{1350}{5} = 270$ mi/h.

Question 6

You leave on a 549-mi trip in order to attend a meeting that will start 10.8 h after you begin your trip.Along the way you plan to stop for dinner.If the fastest you can safely drive is 65 mi/h,what is the longest time you can spend over dinner and still arrive just in time for the meeting?
A)2.4 h
B)2.6 h
C)1.9 h
D)You can't stop at all.

Accepted Answer

The total driving time without stops is 549 mi / 65 mi/h = 8.4 h. Since the total time available is 10.8 h, the longest dinner break possible is 10.8 h - 8.4 h = 2.4 h.

Question 7

The velocity v(t)of a particle as a function of time is given by v(t)= (2.3 m/s)+ (4.1 m/s²)t - (6.2 m/s³)t².What is the average acceleration of the particle between t = 1.0 s and t = 2.0 s? A)-13 m/s² B)-15 m/s² C)13 m/s² D)15 m/s² E)0 m/s²

Accepted Answer

The acceleration is the derivative of velocity with respect to time, so we can find the acceleration function by taking the derivative of v(t):
a(t) = 4.1 - 6.2t
To find the average acceleration between t=1.0 s and t=2.0 s, we need to compute the average of this function over that interval:
a_avg = (1/1)*(∫ from 1 to 2 of 4.1 - 6.2t dt) = (1/1)*[4.1t - 3.1t^2] from 1 to 2 = -15 m/s^2
Therefore, the answer is B, -15 m/s^2.

Question 8

A bat,flying toward the east at 2.0 m/s,emits a shriek that is reflected back to it from a wall that is 20.0 m in front of the bat at the instant the shriek is emitted.Sound travels at 340 m/s in the air.How many milliseconds after emitting the shriek does the bat hear the reflected echo from the wall?

Accepted Answer

The answer of A bat,flying toward the east at 2.0...

Question 9

A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h.What is her average speed for the trip?
A)85 km/h
B)88 km/h
C)90 km/h
D)92 km/h

Accepted Answer

The total distance traveled is (3.0 h * 80 km/h) + (2.0 h * 100 km/h) = 240 km + 200 km = 440 km. The total time is 3.0 h + 2.0 h = 5.0 h. The average speed is total distance / total time = 440 km / 5.0 h = 88 km/h.

Question 10

Arthur and Betty start walking toward each other when they are 100 m apart.Arthur has a speed of 3.0 m/s and Betty has a speed of 2.0 m/s.How long does it take for them to meet?

Accepted Answer

The answer of Arthur and Betty start walking toward each...

Question 11

If a car accelerates at a uniform 4.0 m/s²,how long will it take to reach a speed of 80 km/hr,starting from rest?

Accepted Answer

The answer of If a car accelerates at a uniform...

Question 12

A runner runs around a track consisting of two parallel lines 96 m long connected at the ends by two semicircles with a radius of 49 m.She completes one lap in 100 seconds.What is her average speed?
A)2.5 m/s
B)5.0 m/s
C)10 m/s
D)0 m/s
E)1.3 m/s

Accepted Answer

The length of each semicircle can be found using the formula $C = 2\pi r$, where $r = 49$ m.

$C_{semicircle} = 2\pi(49)/2 = 77\pi$ m

So the total length of the track is:

$96 + 96 + 77\pi + 77\pi = 192 + 154\pi$ m

The runner completes one lap in 100 seconds, so her average speed is:

$average\ speed = \dfrac{distance}{time} = \dfrac{192 + 154\pi}{100}$ m/s

Using a calculator, this is approximately 5.0 m/s.

Therefore, the best choice is (B).

Question 13

A car is traveling north at 1.77m/s.After 12 s its velocity is $14.1 \mathrm {~m} / \mathrm { s }$ in the same direction.Find the magnitude and direction of the car's average acceleration. A)0.30 m/s², south B)2.7 m/s², south C)0.30 m/s², north D)2.7 m/s², north

Accepted Answer

The answer of A car is traveling north at 1.77m/s.After...

Question 14

A motorist makes a trip of 180 miles.For the first 90 miles she drives at a constant speed of 30 mph.At what constant speed must she drive the remaining distance if her average speed for the total trip is to be 40 mph?
A)45 mph
B)50 mph
C)52.5 mph
D)55 mph
E)60 mph

Accepted Answer

The answer of A motorist makes a trip of 180...

Question 15

The position x(t)of a particle as a function of time t is given by the equation x(t)= (3.5 m/s)t - (5.0 m/s²)t².What is the average velocity of the particle between t = 0.30 s and t = 0.40 s?

Accepted Answer

The answer of The position x(t)of a particle as a...

Question 16

If,in the figure,you start from the Bakery,travel to the Cafe,and then to the Art Gallery in 2.00 hours,what is your
(a)average speed?
(b)average velocity?

Accepted Answer

The answer of If,in the figure,you start from the Bakery,travel...

Question 17

An airplane increases its speed at the average rate of 15 m/s².How much time does it take to increase its speed from 100 m/s to 160 m/s? A)17 s B)0.058 s C)4.0 s D)0.25 s

Accepted Answer

We can use the formula:
Δv = aΔt
Where:
Δv = change in speed = (final speed) - (initial speed) = 160 m/s - 100 m/s = 60 m/s
a = acceleration = 15 m/s²
Δt = time taken

Substituting the values:
60 m/s = 15 m/s² × Δt
Δt = 4.0 s

Therefore, it takes 4.0 seconds for the airplane to increase its speed from 100 m/s to 160 m/s.

Question 18

A car that is initially moving at 7.50 m/s begins to accelerate forward uniformly at 0.550 m/s². (a)How long after beginning to accelerate does it take the car to move 3.50 km? (b)How fast is the car moving just as it has traveled 3.50 km?

Accepted Answer

The answer of A car that is initially moving at...

Question 19

A race car circles 10 times around a circular 8.0-km track in 20 min.Using SI units
(a)what is its average speed for the ten laps?
(b)what is its average velocity for the ten laps?

Accepted Answer

The answer of A race car circles 10 times around...

Question 20

Human reaction times are worsened by alcohol.How much further (in feet)would a drunk driver's car travel before he hits the brakes than a sober driver's car? Assume that both are initially traveling at 50.0 mi/h and their cars have the same acceleration while slowing down,and that the sober driver takes 0.33 s to hit the brakes in a crisis,while the drunk driver takes 1.0 s to do so.(5280 ft = 1 mi)

Accepted Answer

The answer of Human reaction times are worsened by alcohol.How...

Quiz 2: Kinematics: Motion in One Dimension

A racquetball strikes a wall with a speed of 30 m/s and rebounds in the opposite direction with a speed of 26 m/s.The collision takes 20 ms.What is the average acceleration of the ball during the collision with the wall?

A water rocket can reach a speed of 75 m/s in 0.050 seconds from launch.What is its average acceleration?

The captain orders his starship to accelerate from rest at a rate of "1 g" (1 g = 9.8 m/s²).How many days does it take the starship to reach 10% the speed of light? (Light travels at 3.0 × 10⁸ m/s.)

A runner runs around a track consisting of two parallel lines 96 m long connected at the ends by two semicircles with a radius of 49 m.She completes one lap in 100 seconds.What is her average velocity?

An airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h north for 750 miles.What is the average speed for the trip?

You leave on a 549-mi trip in order to attend a meeting that will start 10.8 h after you begin your trip.Along the way you plan to stop for dinner.If the fastest you can safely drive is 65 mi/h,what is the longest time you can spend over dinner and still arrive just in time for the meeting?

The velocity v(t) of a particle as a function of time is given by v(t) = (2.3 m/s) + (4.1 m/s²) t - (6.2 m/s³) t².What is the average acceleration of the particle between t = 1.0 s and t = 2.0 s?

A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h.What is her average speed for the trip?

Arthur and Betty start walking toward each other when they are 100 m apart.Arthur has a speed of 3.0 m/s and Betty has a speed of 2.0 m/s.How long does it take for them to meet?

If a car accelerates at a uniform 4.0 m/s²,how long will it take to reach a speed of 80 km/hr,starting from rest?

A runner runs around a track consisting of two parallel lines 96 m long connected at the ends by two semicircles with a radius of 49 m.She completes one lap in 100 seconds.What is her average speed?

A car is traveling north at 1.77m/s.After 12 s its velocity is $14.1 \mathrm {~m} / \mathrm { s }$ in the same direction.Find the magnitude and direction of the car's average acceleration.

A motorist makes a trip of 180 miles.For the first 90 miles she drives at a constant speed of 30 mph.At what constant speed must she drive the remaining distance if her average speed for the total trip is to be 40 mph?

The position x(t)of a particle as a function of time t is given by the equation x(t)= (3.5 m/s)t - (5.0 m/s²)t².What is the average velocity of the particle between t = 0.30 s and t = 0.40 s?

If,in the figure,you start from the Bakery,travel to the Cafe,and then to the Art Gallery in 2.00 hours,what is your (a)average speed? (b)average velocity?

An airplane increases its speed at the average rate of 15 m/s².How much time does it take to increase its speed from 100 m/s to 160 m/s?

A car that is initially moving at 7.50 m/s begins to accelerate forward uniformly at 0.550 m/s². (a)How long after beginning to accelerate does it take the car to move 3.50 km? (b)How fast is the car moving just as it has traveled 3.50 km?

A race car circles 10 times around a circular 8.0-km track in 20 min.Using SI units (a)what is its average speed for the ten laps? (b)what is its average velocity for the ten laps?

Quiz 2: Kinematics: Motion in One Dimension

A racquetball strikes a wall with a speed of 30 m/s and rebounds in the opposite direction with a speed of 26 m/s.The collision takes 20 ms.What is the average acceleration of the ball during the collision with the wall?

A water rocket can reach a speed of 75 m/s in 0.050 seconds from launch.What is its average acceleration?

The captain orders his starship to accelerate from rest at a rate of "1 g" (1 g = 9.8 m/s2).How many days does it take the starship to reach 10% the speed of light? (Light travels at 3.0 × 108 m/s.)

A runner runs around a track consisting of two parallel lines 96 m long connected at the ends by two semicircles with a radius of 49 m.She completes one lap in 100 seconds.What is her average velocity?

An airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h north for 750 miles.What is the average speed for the trip?

You leave on a 549-mi trip in order to attend a meeting that will start 10.8 h after you begin your trip.Along the way you plan to stop for dinner.If the fastest you can safely drive is 65 mi/h,what is the longest time you can spend over dinner and still arrive just in time for the meeting?

The velocity v(t) of a particle as a function of time is given by v(t) = (2.3 m/s) + (4.1 m/s2) t - (6.2 m/s3) t2.What is the average acceleration of the particle between t = 1.0 s and t = 2.0 s?

A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h.What is her average speed for the trip?

Arthur and Betty start walking toward each other when they are 100 m apart.Arthur has a speed of 3.0 m/s and Betty has a speed of 2.0 m/s.How long does it take for them to meet?

If a car accelerates at a uniform 4.0 m/s2,how long will it take to reach a speed of 80 km/hr,starting from rest?

A runner runs around a track consisting of two parallel lines 96 m long connected at the ends by two semicircles with a radius of 49 m.She completes one lap in 100 seconds.What is her average speed?

A car is traveling north at 1.77m/s.After 12 s its velocity is 14.1 m/s14.1 \mathrm {~m} / \mathrm { s }14.1 m/s in the same direction.Find the magnitude and direction of the car's average acceleration.

A motorist makes a trip of 180 miles.For the first 90 miles she drives at a constant speed of 30 mph.At what constant speed must she drive the remaining distance if her average speed for the total trip is to be 40 mph?

The position x(t)of a particle as a function of time t is given by the equation x(t)= (3.5 m/s)t - (5.0 m/s2)t2.What is the average velocity of the particle between t = 0.30 s and t = 0.40 s?

If,in the figure,you start from the Bakery,travel to the Cafe,and then to the Art Gallery in 2.00 hours,what is your (a)average speed? (b)average velocity?

An airplane increases its speed at the average rate of 15 m/s2.How much time does it take to increase its speed from 100 m/s to 160 m/s?

A car that is initially moving at 7.50 m/s begins to accelerate forward uniformly at 0.550 m/s2. (a)How long after beginning to accelerate does it take the car to move 3.50 km? (b)How fast is the car moving just as it has traveled 3.50 km?

A race car circles 10 times around a circular 8.0-km track in 20 min.Using SI units (a)what is its average speed for the ten laps? (b)what is its average velocity for the ten laps?

The captain orders his starship to accelerate from rest at a rate of "1 g" (1 g = 9.8 m/s²).How many days does it take the starship to reach 10% the speed of light? (Light travels at 3.0 × 10⁸ m/s.)

The velocity v(t) of a particle as a function of time is given by v(t) = (2.3 m/s) + (4.1 m/s²) t - (6.2 m/s³) t².What is the average acceleration of the particle between t = 1.0 s and t = 2.0 s?

If a car accelerates at a uniform 4.0 m/s²,how long will it take to reach a speed of 80 km/hr,starting from rest?

A car is traveling north at 1.77m/s.After 12 s its velocity is $14.1 \mathrm {~m} / \mathrm { s }$ in the same direction.Find the magnitude and direction of the car's average acceleration.

The position x(t)of a particle as a function of time t is given by the equation x(t)= (3.5 m/s)t - (5.0 m/s²)t².What is the average velocity of the particle between t = 0.30 s and t = 0.40 s?

An airplane increases its speed at the average rate of 15 m/s².How much time does it take to increase its speed from 100 m/s to 160 m/s?

A car that is initially moving at 7.50 m/s begins to accelerate forward uniformly at 0.550 m/s². (a)How long after beginning to accelerate does it take the car to move 3.50 km? (b)How fast is the car moving just as it has traveled 3.50 km?