Forces Chapter 10

What is an example of exerting force?

Pushing/pulling anything

What happens when two forces act in the same direction?

They add together

The force of gravity on a person or object on the surface of a planet is called

Friction

Which of the following is an example of rolling friction?

Anything rolling

When the only force acting on a falling object is gravity, then the object is said to be

In free fall

Air resistance is a type of

Friction

The law of universal gravitation states that any two objects in the universe, without exception

Attract each other

In physical science, a push or a pull is called a

Force

The amount of matter in an object is called its

Mass

Which of the following is an example of increasing friction intentionally

Throwing sand on an icy driveway

The force that pulls falling objects toward Earth is called

Gravity

Objects falling through air experience a type of friction called

Air resistance

The SI unit for force is the

Newton

Balanced forces acting on an object

Never change the object’s motion

The tendency of an object to resist change in its motion is known as

Inertia

How can you increase the momentum of an object?

By increasing mass or velocity

According to the law of conservation of momentum, when two objects collide in the absence of friction,

Momentum is transferred and not lost

The total momentum of a group of objects is conserved unless

Outside forces act on the objects

According to Newton’s third law of motion, when a hammer strikes and exerts force on a nail, the nail

Exerts an equal force on the hammer

What happens when a unbalanced force acts on an object?

The objects in motion will accelerate

Which of these objects would exhibit the greatest resistance to a change in it’s motion?

Heaviest mass

Newton’s second law of motion states the relationship of mass, acceleration, and force. It says that

F = Mass x Acceleration

As the force applied to the object is increases, the objects will also increase.

Acceleration

A 300 N force acts on a 20 kg object. The acceleration of the object is

15 meters per second squared

Compared to a sports car moving at 30 mph, the same sports car moving at 60 mph has

Twice as much momentum

One way to increase acceleration is by

Decreasing mass, Increasing force

The product of an object’s mass and velocity is called its

Momentum

A person standing on roller skates is holding a heavy rock. If he throws the rock horizontally to the right, what will be his resulting motion?

To the left

The amount of gravity between two objects depends on their masses and

Distance between them

Forces can be added together only if they are

Acting in the same direction

A student pushes a lawnmower with a force of 15 N. What is the force exerted by the mower on his hands?

15 N

The momentum of an object is in the same direction as its

Velocity

What happens when two forces act in the same direction?

Added together

That force that one surface exerts on another when the two rub against each other is called

Friction

Mass times acceleration equals the net force acting on an object according to which of Newton’s laws?

2 nd Law

Which has more momentum, a semi-truck moving at 30 mph or a Chevy S10 truck moving at 30 mph?

Semi-truck

The greater the mass of an object,

The greater the inertia

Balanced forces acting on an object

Never change object’s motion