Physical Science II Ch. 2

It is important to know that the term inertia refers to

If gravity between the Sun and Earth suddenly vanished, Earth would continue moving in a(n)

Newton's second law of motion links force, acceleration, and

A cart is pushed and undergoes a certain acceleration. Consider how the acceleration would compare if it were pushed with twice the net force while its mass increased by four. Then its acceleration would be

The reason a 20-kg rock falls no faster than a 10-kg rock in free fall is that

A heavy parachutist has a greater terminal speed compared with a lighter parachutist with the same size parachute because the heavier person

Whenever one object exerts a force on a second object, the second object exerts a force on the first that

The force that directly propels a motor scooter along a highway is that provided by the

How hard a boxer's punch lands depends on the

The primary physics that got humans to the Moon was

Is inertia a property of matter or a force of some kind?

What concept was missing from people's minds in the 16th century when they couldn't believe Earth was moving?

When a bird lets go of a branch and drops to the ground below, why doesn't the moving Earth sweep away from the dropping bird?

What kind of path would the planets follow if suddenly their attraction to the Sun no longer existed?

State Newton's second law

Is acceleration directly or inversely proportional to force? Give an example

Is acceleration directly or inversely proportional to mass? Give an example

If the mass of a sliding block is tripled at the same time that the net force on it is tripled, how does the resulting acceleration compare to the original acceleration?

What is the net force that acts on a 10-N freely falling object

Why doesn't a heavy object accelerate more than a light object when both are freely falling?

What is the net force that acts on a 10-N falling object when it encounters 4 N of air resistance? 10 N of air resistance?

What two principal factors affect the force of air resistance on a falling object?

If two objects of the same size fall through air at different speeds, which encounters the greater air resistance?

Why does a heavy parachutist fall faster than a lighter parachutist who wears the same size parachute?

In this chapter, we treated force as a push or pull, now we say it is part of an interaction. Is a force a push or pull, or part of an interaction?

How many forces are required for a single interaction?

When you push against a wall with your fingers, they bend because they experience a force. Identify this force.

A boxer can hit a heavy bag with great force. Why can't he hit a sheet of tissue paper in midair with the same amount of force?

State Newton's third law.

onsider hitting a baseball with a bat. If we call the force of the bat against the ball the action force, what is the reaction force?

If the force that acts on a cannonball and the force that acts on the recoiling cannon from which it is fired are equal in magnitude, why do the cannonball and the cannon have very different accelerations?

Is it correct to say that action and reaction forces always act on different bodies? Defend your answer.

If body A and body B are both within a system, can forces between them affect the acceleration of the system?

In terms of forces, what is necessary to accelerate a system?

Identify the force that propels a rocket into space.

How does a helicopter get its lifting force?

To what law of physics do we refer when we say you cannot touch without being touched?

Which of Newton's laws focuses on inertia? Which on acceleration? Which on action-reaction?

A simple rearrangement of Newton's second law gives Fnet=ma. Find a net force that is needed to give a 9.0-kg package an acceleration of 7.0 m/s2 . (Note: The units kg?m/s2 and N are equivalent.)

In the textbook acceleration is defined as a=?v/?t. Use this formula to find the acceleration of a cart on an inclined plane that gains 7.0 m/s each 1.2 s

In the textbook we learn that the cause of acceleration is given by Newton's second law: a=Fnet/m. Find the acceleration that can result from a net force of 18 N exerted on a 4.0-kg cart. (Note: The unit N/kg is equivalent to m/s2.)

Knowing that a 0.50-kg object weighs 5.0 N , find the acceleration of a 0.50-kg stone in free fall .

When two horizontal forces are exerted on the car, 250 N forward and 240 N backward, the car undergoes acceleration. What additional force is needed to produce non-accelerated motion?

A business jet of mass 40000 kg takes off when the thrust for each of two engines is 32000 N. Find its acceleration.

Calculate the horizontal force that must be applied to a 0.50-kg puck to accelerate on a horizontal friction-free air table with the same acceleration it would have if it were dropped and fell freely.

A force F acts in the forward direction on a cart of mass m. A friction force f opposes this motion. Use Newton's second law and express the acceleration of the cart.

Does it follow that the Moon also pulls on Earth?

A friend says that Ale´ cannot push on the tree unless the tree pushes back on her, and another friend says that if Ale´ pushes quickly, the tree won't push as hard on her. Which friend do you agree with, and why?