Physics

When you pull an object, such as a table, across the floor, the forward force by

When you pull an object, such as a table, across the floor, the forward force by

When you pull an object, such as a table, across the floor, the forward force by you on the table is equal but opposite to the backward force by the table on you. It seems as though these two forces should balance out, so that the table can't be

einsteindude   194   1 Reply

mel!811

One force acting on a falling apple is the apple's weight. Which of the followin

One force acting on a falling apple is the apple's weight. Which of the followin

One force acting on a falling apple is the apple's weight. Which of the following is the best description of the other member of the "force pair" [of which the apple's weight is one member]?       

A) Air

einsteindude   388   1 Reply

mel!811

One force acting on your body right now is your weight. Which of the following i

One force acting on your body right now is your weight. Which of the following i

One force acting on your body right now is your weight. Which of the following is the best description of the other member of the "force pair" [of which your weight is one member]?       

A) The gravitational force

einsteindude   257   1 Reply

mel!811

A stationary firecracker explodes, breaking into two parts of equal mass. One p

A stationary firecracker explodes, breaking into two parts of equal mass. One p

A stationary firecracker explodes, breaking into two parts of equal mass.  One part is moving north at 20 m/s.  The velocity of the other part is     

A) impossible to predict without more information.
B) 20

einsteindude   477   1 Reply

mel!811

You would be richest if your hunk of gold had a mass of one kilogram

You would be richest if your hunk of gold had a mass of one kilogram

You would be richest if your hunk of gold had a mass of one kilogram       
A) on the moon.
B) on Earth.
C) Actually it wouldn't make any difference.

einsteindude   356   1 Reply

mel!811

You would be richest if your hunk of gold weighed 10 newtons

You would be richest if your hunk of gold weighed 10 newtons

You would be richest if your hunk of gold weighed 10 newtons       
A) on the moon.
B) on Earth.
C) Actually it wouldn't make any difference.

einsteindude   272   1 Reply

mel!811

Would you be richer if you had a hunk of gold whose weight is 1 newton on the mo

Would you be richer if you had a hunk of gold whose weight is 1 newton on the mo

Would you be richer if you had a hunk of gold whose weight is 1 newton on the moon, or one whose weight is 1 newton on Earth, and why?       

A) 1 newton on the moon, because then the gold's weight on the moon would be

einsteindude   633   1 Reply

mel!811

A rocket taking off straight upward develops a thrust of 10,000 newtons. The roc

A rocket taking off straight upward develops a thrust of 10,000 newtons. The roc

A rocket taking off straight upward develops a thrust of 10,000 newtons. The rocket weighs 2,000 newtons. The net force on the rocket, neglecting air resistance, is     

A) 12, 000 newtons.
B) 2,000 newtons.
C)

einsteindude   290   1 Reply

mel!811

A certain grapefruit on Earth has a mass of one kilogram and a weight of one new

A certain grapefruit on Earth has a mass of one kilogram and a weight of one new

A certain grapefruit on Earth has a mass of one kilogram and a weight of one newton. When the grapefruit is on the moon its mass is       

A) one kilogram.       B) ten newtons.
C) less than ten newtons.

einsteindude   267   1 Reply

mel!811

A one kilogram grapefruit weighs ten newtons. Suppose we take this grapefruit to

A one kilogram grapefruit weighs ten newtons. Suppose we take this grapefruit to

A one kilogram grapefruit weighs ten newtons. Suppose we take this grapefruit to the moon. The force of gravity on the grapefruit will then be       

A) ten newtons.
B) one kilogram.
C) less than one kilogram.

einsteindude   427   1 Reply

mel!811

A car weighing 5000 N is traveling along a straight level road powered by a forw

A car weighing 5000 N is traveling along a straight level road powered by a forw

A car weighing 5000 N is traveling along a straight level road powered by a forward drive force of 500 N. The force of air resistance is 200 N, and rolling resistance is 100 N. The net force on the car is       

A) 300 N bac

einsteindude   379   1 Reply

mel!811

A car weighing 5000 N is traveling along a straight level road powered by a forw

A car weighing 5000 N is traveling along a straight level road powered by a forw

A car weighing 5000 N is traveling along a straight level road powered by a forward drive force of 500 N. The force of air resistance is 200 N, and rolling resistance is 100 N. The car's acceleration is       

A) in the

einsteindude   536   1 Reply

mel!811

An auto moves at a steady 50 mph down a straight level road. The direction of th

An auto moves at a steady 50 mph down a straight level road. The direction of th

An auto moves at a steady 50 mph down a straight level road. The direction of the force of air resistance on the car is       

A) backward.
B) zero.
C) sideways.
D) downward.
E) forward.

einsteindude   326   1 Reply

mel!811

An auto moves at a steady 50 mph down a straight level road. The net force on th

An auto moves at a steady 50 mph down a straight level road. The net force on th

An auto moves at a steady 50 mph down a straight level road. The net force on the auto is       
A) backward.
B) zero.
C) forward.
D) sideways.
E) downward.

einsteindude   302   1 Reply

mel!811

An auto moves at a steady 50 mph down a straight level road. Which of the follow

An auto moves at a steady 50 mph down a straight level road. Which of the follow

An auto moves at a steady 50 mph down a straight level road. Which of the following is the forward drive force on the auto?       

A) The drive force is actually zero in this example, because the auto is moving at a constant

einsteindude   370   1 Reply

mel!811

An auto travels down a straight, level road at constant speed. One force that ac

An auto travels down a straight, level road at constant speed. One force that ac

An auto travels down a straight, level road at constant speed. One force that acts on the auto is       
A) gravity pushing upward on the auto.
B) the auto pushing downward on the road.
C) the road pushing upward on th

einsteindude   385   1 Reply

mel!811

Jet planes operate by (Multiple Choice)

Jet planes operate by (Multiple Choice)

Jet planes operate by       
A) ejecting ions out the back end of the engine.
B) sucking in air and blowing it rapidly out the back of the engine by means of propeller blades inside the engine.
C) magic.
D) rocke

einsteindude   215   1 Reply

mel!811

Suppose that we wish to find the "net force" on an automobile, in order to apply

Suppose that we wish to find the "net force" on an automobile, in order to apply

Suppose that we wish to find the "net force" on an automobile, in order to apply Newton's law of motion to the motion of the automobile. As part of the net force, do we need to include "internal frictional forces" due to inte

einsteindude   310   1 Reply

mel!811

The basic physical principal principle that explains the operation of rocket eng

The basic physical principal principle that explains the operation of rocket eng

The basic physical principal principle that explains the operation of rocket engines is       
A) Galileo's principle of falling.
B) the atomic hypothesis.
C) the law of force pairs.
D) the law of inertia.

einsteindude   376   1 Reply

mel!811

The "drive force" that pushes a car forward is

The "drive force" that pushes a car forward is

The "drive force" that pushes a car forward is       
A) actually zero whenever the car has no acceleration.
B) exerted by the engine pushing forward against the axle.
C) exerted by the road pushing forward a

einsteindude   325   1 Reply

mel!811

The "drive force" that pushes a car forward is

The "drive force" that pushes a car forward is

The "drive force" that pushes a car forward is       
A) the force of the engine turning the drive tires.
B) the push of the drive tires against the road.
C) the force of the expanding gases inside the engine

einsteindude   502   1 Reply

mel!811

An object's "momentum" is defined as

An object's "momentum" is defined as

An object's "momentum" is defined as       
A) its force time is velocity.
B) its weight times its speed.
C) its mass times its speed.
D) its force times its distance.
E) its mass times its veloc

einsteindude   308   1 Reply

mel!811

It's harder to stop or turn a moving supertanker than a small speedboat because

It's harder to stop or turn a moving supertanker than a small speedboat because

It's harder to stop or turn a moving supertanker than a small speedboat because     
A) the supertanker has a larger momentum. 
B) the supertanker has more force. 
C) the speed boat has a larger velocit

einsteindude   443   1 Reply

mel!811

Can two pool balls, both of them moving, have a total momentum of zero? A)

Can two pool balls, both of them moving, have a total momentum of zero? A)

Can two pool balls, both of them moving, have a total momentum of zero?     
A) No, because any moving object has momentum. 
B) No, because they both have energy. 
C) Yes, but only at the instant that they c

einsteindude   398   1 Reply

mel!811

Which of the following principles explains why guns recoil?

Which of the following principles explains why guns recoil?

Which of the following principles explains why guns recoil?     
A) Conservation of energy.
B) Conservation of momentum.
C) Newton's law of motion.
D) The law of inertia.
E) None of the above.

einsteindude   291   1 Reply

mel!811

Are there any kinds of situations in which the momentum of a moving system is no

Are there any kinds of situations in which the momentum of a moving system is no

Are there any kinds of situations in which the momentum of a moving system is not conserved?       
A) No, because the momentum of any system is always conserved. 
B) No, because the law of inertia demands that an

einsteindude   207   1 Reply

mel!811

Is there a force on the moon, and how do you know?

Is there a force on the moon, and how do you know?

Is there a force on the moon, and how do you know?       
A) No, because the moon moves at an unchanging speed.
B) No, because the moon is not accelerated.
C) Yes, because there must be a force pulling outward on the m

einsteindude   278   1 Reply

mel!811

A pool ball moving at 3 m/s collides head-on with an identical pool ball that's

A pool ball moving at 3 m/s collides head-on with an identical pool ball that's

A pool ball moving at 3 m/s collides head-on with an identical pool ball that's initially at rest. Just after the collision, the second ball moves away at 2 m/s while the first ball     

A) moves at 1 m/s in the same d

einsteindude   393   1 Reply

mel!811

A small car and a large truck collide head-on. During the collision, the small

A small car and a large truck collide head-on. During the collision, the small

A small car and a large truck collide head-on.  During the collision, the small car experiences       
A) A much larger acceleration than the truck.
B) A much larger force than the truck.
C) A much larger change in

einsteindude   500   1 Reply

mel!811

A 39-kg girl standing at rest on slippery (frictionless) ice catches a 1-g ball

A 39-kg girl standing at rest on slippery (frictionless) ice catches a 1-g ball

A 39-kg girl standing at rest on slippery (frictionless) ice catches a 1-g ball moving at 10 m/s.  Just afterward, the girl is     

A) moving at 0.5 m/s.
B) moving at 2 m/s.
C) moving at 4 m/s.
D) at res

einsteindude   689   1 Reply

mel!811

An important similarity that Newton noticed between a falling apple and the moon

An important similarity that Newton noticed between a falling apple and the moon

An important similarity that Newton noticed between a falling apple and the moon was that       
A) the net force on both is toward the center of Earth.
B) the accelerations of both are toward the center of Earth.
C) B

einsteindude   363   1 Reply

mel!811

The figure shows the moon orbiting around Earth. Suppose that the force of gravi

The figure shows the moon orbiting around Earth. Suppose that the force of gravi

The figure shows the moon orbiting around Earth. Suppose that the force of gravity between Earth and moon suddenly "switched off." Which of the three arrows point in the direction that the moon would move after gravity vanished?   

einsteindude   466   1 Reply

mel!811

As the moon circles Earth, the net force on it is

As the moon circles Earth, the net force on it is

As the moon circles Earth, the net force on it is       
A) directed outward away from Earth.
B) directed inward toward Earth.
C) forward.
D) backward.
E) zero.

einsteindude   565   1 Reply

mel!811

NASA satellites stay up because

NASA satellites stay up because

NASA satellites stay up because       
A) their rocket engines hold them above Earth's surface.
B) they are moving so fast that they are able to "fall" around Earth.
C) they are away from Earth's gr

einsteindude   292   1 Reply

mel!811

Suppose that the force of gravity between the sun and Earth suddenly stopped ope

Suppose that the force of gravity between the sun and Earth suddenly stopped ope

Suppose that the force of gravity between the sun and Earth suddenly stopped operating. What would happen?       

A) Earth would fall directly inward, into the sun.
B) Earth would continue orbiting the sun, but objects

einsteindude   306   1 Reply

mel!811

The law of gravity was invented by

The law of gravity was invented by

The law of gravity was invented by       
A) Copernicus.
B) Newton.
C) Ptolemy.
D) Galileo.
E) Kepler.

einsteindude   270   1 Reply

mel!811

The moon's acceleration is directed

The moon's acceleration is directed

The moon's acceleration is directed       
A) outward, away from Earth.
B) backward, opposite to its direction of motion.
C) forward, along its direction of motion.
D) zero.
E) inward, toward the cente

einsteindude   267   1 Reply

mel!811

What similarity did Isaac Newton perceive between a falling apple and the moon?

What similarity did Isaac Newton perceive between a falling apple and the moon?

What similarity did Isaac Newton perceive between a falling apple and the moon?       
A) The velocities of both are directed toward Earth's center.
B) Both have a velocities and accelerations directed toward Earth'

einsteindude   701   1 Reply

mel!811

Astronauts inside Earth satellites such as the space shuttle are usually said to

Astronauts inside Earth satellites such as the space shuttle are usually said to

Astronauts inside Earth satellites such as the space shuttle are usually said to be "in orbit" around Earth. Are you "in orbit" around anything?       

A) Yes, around the sun due to Earth's motion th

einsteindude   358   1 Reply

mel!811

Is the moon accelerated? (Multiple Choice Question)

Is the moon accelerated? (Multiple Choice Question)

Is the moon accelerated?       
A) No, because there is no gravity in space.
B) No, because the gravitational force on it is balanced by the centrifugal force.
C) Yes, its acceleration is directed forward, along its dir

einsteindude   197   1 Reply

mel!811