Question 1

Compared with your mass on Earth,your mass out in space among the stars would be:

Accepted Answer

Your mass does not change based on your location. Mass is a measure of the amount of matter in an object and is independent of gravity or location. Therefore, your mass would be the same both on Earth and in space.

Question 2

For the angular momentum of an object to be conserved (i.e.,to not change),the:

Accepted Answer

Conservation of angular momentum requires that the net torque acting on an object is zero. This means that an object can have an external torque acting on it, as long as the sum of other torques balances it out. Therefore, answer choices A, B, and D are not necessary for conservation of angular momentum.

Question 3

The angular momentum of an object depends ONLY on:

Accepted Answer

The answer of The angular momentum of an object depends...

Question 4

The strength of gravity on Mars is about 40% of that on Earth.If you were to take a standard red brick to Mars,which property of the brick would be significantly different on Mars than on Earth?

Accepted Answer

The strength of gravity affects the weight of an object, which is the force with which it is attracted towards the center of the planet. Therefore, the weight of the red brick would be significantly different on Mars compared to Earth, as it would weigh only 40% of its weight on Earth due to the weaker gravitational pull. Mass, color, and volume would all remain the same as they are intrinsic properties of the brick.

Question 5

On the Moon,where gravity is 1/6 of Earth's gravity,which of the following activities would an astronaut NOT find easier to carry out?

Accepted Answer

Slowing down and stopping would actually be more difficult on the moon due to the lower gravity. It would be easier for an astronaut to keep moving and maintain momentum since it would take less force to start and stop moving.

Question 6

A gravitational force is exerted by a large mass on a small mass a certain distance away.If I increase the separation to three times its original value and then switch the large and small masses,what will happen to the gravitational force?

Accepted Answer

The gravitational force is inversely proportional to the square of the distance between the two masses. Increasing the separation to three times its original value decreases the force by a factor of 3^2, which is 9. Switching the masses does not affect the magnitude of the force.

Question 7

I have a massive purple object in my laboratory.If I were to take it to the Moon,which of its characteristics would be guaranteed to change?

Accepted Answer

Weight would change because it depends on the gravitational force, which is weaker on the Moon than on Earth.

Question 8

The strength of gravity on Mars is about 40% of that on Earth.If you were to visit Mars,what would happen to your mass and weight compared with when you were on Earth?

Accepted Answer

Your mass is a measure of the amount of matter in your body and is independent of gravity. So your mass would not change whether you were on Earth or Mars.
However, your weight is a measure of the force acting on your body due to gravity. As gravity on Mars is weaker than on Earth, the force acting on your body would be less, and therefore your weight would be less. So choice D is the correct answer.

Question 9

A rocket that is accelerated by the force from the ejection of large quantities of hot gases represents an example of which physical law originally stated by Newton?

Accepted Answer

Newton's third law of motion states that for every action, there is an equal and opposite reaction. In the case of a rocket, the action is the ejection of hot gases out of the back of the rocket, and the reaction is the force propelling the rocket forward.

Question 10

The strength of gravity on Mars is about 40% of that on Earth.If your mass on Earth is 60 kg,what would your WEIGHT be on Mars?

Accepted Answer

The answer of The strength of gravity on Mars is...

Question 11

Two solid spheres of equal size and mass are joined by a spring-loaded,extendible rod.The whole unit is spinning like a baton (end-over-end)five times per second.Suddenly,the rod stretches,pushing the spheres farther apart.What change takes place as a result of the stretching?

Accepted Answer

The angular momentum is conserved, so when the rod stretches and the moment of inertia increases, the rate of spin (angular velocity) decreases.

Question 12

A person standing on bathroom scales sees a reading of 148 pounds.This person is acted on by:

Accepted Answer

The person is acted upon by two forces of equal size but in opposite directions: the gravitational force pulling them down (their weight) and the normal force from the scale pushing them up, which is why the scale shows a reading of 148 pounds.

Question 13

The action and reaction forces referred to in Newton's third law of motion:

Accepted Answer

Newton's third law states that for every action force, there is an equal and opposite reaction force. These two forces act on different bodies, not the same body. Therefore, the correct choice is D.

Question 14

Was Newton's derived version of Kepler's third law the same as the version Kepler discovered by trial and error?

Accepted Answer

Kepler's third law originally only related the period of a planet's orbit to its distance from the sun, while Newton's version adjusted for the planet's mass.

Question 15

Which concept in Newton's mechanics provides an answer to the question: Why don't the planets fall into the Sun?

Accepted Answer

According to Newton's laws of motion, an object in motion will continue in a straight line at a constant speed unless acted upon by an external force. In the case of the planets, they are constantly moving around the Sun because of their angular momentum, which is a conserved quantity. This means that as long as the planets' angular momentum remains constant, they will not fall into the Sun. Therefore, the conservation of angular momentum provides the best answer to the question of why the planets do not fall into the Sun.

Question 16

If you travel from Earth to the Moon,which of the following quantities will be unchanged?

Accepted Answer

Mass is an intrinsic property of an object and does not change with location or environment. Therefore, your mass would be unchanged during travel from Earth to the Moon.

The other options, A) the gravitational force acting on you, C) your weight in pounds, and D) your weight in Newtons, all depend on the gravitational field and therefore would change during travel from Earth to the Moon.

Question 17

What is the size of the force you exert on Earth compared with the force Earth exerts on you as you stand on its surface?

Accepted Answer

According to Newton's third law of motion, for every action (force) there is an equal and opposite reaction (force). Therefore, the Earth exerts a force on you equal in magnitude and opposite in direction to the force you exert on Earth. The size of the force depends on your mass and the distance between you and the center of the Earth, which is much larger than your mass, so the force you exert on Earth is very small compared to the force Earth exerts on you. Thus, the correct answer is D, the forces are the same.

Question 18

A diver weighing 138 pounds has just dived up and out from the high board and is doing a back flip before starting to descend toward the water.How much force does the diver exert on Earth while doing the back flip?

Accepted Answer

According to Newton's third law of motion, every action has an equal and opposite reaction. Therefore, the force the diver exerts on Earth is equal to the diver's weight, which is 138 pounds.

Question 19

The strength of gravity on Mars is about 40% of that on Earth.If your mass on Earth is 60 kg,what would your MASS be on Mars?

Accepted Answer

Mass is a measure of the amount of matter in an object and does not change with location. Therefore, your mass on Mars would still be 60 kg.

Question 20

The old story about the person who sneezed so hard that he fell off his barstool is an exaggerated illustration of which physical law?

Accepted Answer

Newton's third law states that for every action, there is an equal and opposite reaction. The force of the sneeze could cause a reaction force that might push the person off the barstool.

Quiz 2: Gravitation and the Waltz of the Planets