Chapter 3 - Newton's First Law (Inertia)

Friction...

(all of the above) -comes from microscopic bumps that act as obstructions to the object's motion. -is the name given to the force acting between surfaces sliding past one another. -acts in a direction that opposes the motion of an object.

The law of inertia states that an object

(all of the above) -will continue moving at the same velocity unless an outside force acts on it. -will continue moving in a straight line unless an outside force acts on it. -that is not moving will never move unless a force acts on it. -at rest will remain at rest unless acted on by an outside force.

On the surface of Jupiter, the acceleration due to gravity is about 3 times that of Earth. What would be the mass of a 0.60-kg rock on Jupiter?

0.60 kg (mass is the same anywhere)

The mass of a lamb that weighs 110 N is about

11 kg.

How much does a 2.0-kg bag of grass seed weigh?

19.6 N

How much (in newtons) does a 30.0 kg of tools weigh?

300 N

On the surface of Jupiter, the acceleration due to gravity is about 3 times that on Earth. How much would a 130-kg rock weigh on Jupiter?

3900 kg

On the moon, the acceleration due to gravity is 1/6 that on Earth. What would be the weight of 0.4 kg of bologna on the moon?

4/6 or 0.66 kg

A person weighs 660 N. What is the mass of the person?

66.0 kg

A bag of sports equipment has a mass of 10.0 kilograms and a weight of

98 N

An astronaut weighs the same on Earth as in space.

False

If you were to slide a hockey puck across a frictionless ice rink, there must be a horizontal force on it to keep it in motion.

False

The SI unit of force is the kilogram.

False

The SI unit of mass is the newton

False

The amount of matter in an object is its weight.

False

The force due to gravity acting on an object is its mass

False

Which has more mass, a kilogram of feathers or a kilogram of iron?

Neither—they both have the same mass.

Galileo found that a ball rolling down one inclined plane would roll how far up another inclined plane?

To nearly its original height

A force can be simply defined as a push or a pull.

True

An astronaut has the same mass on Earth as in space.

True

Friction refers to the force between two surfaces that are sliding past each other.

True

Inertia is the property that every material object has; inertia resists changes in an object's state of motion.

True

Suppose you are on an airplane moving at high speed. If you flip a coin straight up it will land in your lap rather than a great distance behind you. Explain.

You, the coin, and the air are all moving horizontally at the same speed. When you flip a coin into the air, it will continue moving horizontally at that speed (Newton's first law).

The law of inertia applies to

both moving and nonmoving objects.

An object following a straight-line path at constant speed

has zero acceleration.

One object has twice as much mass as another object. The first object also has twice as much

inertia

Compared to its weight on Earth, a 10-kg object on the moon will weigh

less.

Friction is a force that always acts

opposite to an object's motion.

If the force of gravity suddenly stopped acting on the planets, they would

spiral slowly away from the sun.

You would have the largest mass of gold if your chunk of gold weighed 1 N on

the moon.

An object weighs 20 N on Earth. A second object weighs 20 N on the moon. Which has the greater mass?

the one on the moon

Compared to its mass on Earth, the mass of a 10-kg object on the moon is

the same.

After a cannonball is fired into frictionless space, the amount of force needed to keep it going equals

zero, since no force is necessary to keep it moving.

The force required to maintain an object at a constant speed in free space is equal to

zero.