Chapter 6 Forces

Forces can be added together only if they are...

• acting on the same object

• balanced forces

• unaffected by gravity

• substantial

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

According to Newton's 3rd Law of Motion, when a hammer strikes and exerts a force on a nail, the nail

• creates friction with the hammer.

• disappears into the wood.

• exerts an equal and opposite force on the hammer.

• moves at constant speed.

What happens when two forces act in the same direction?

• They cancel each other out.

• The stronger one prevails.

• Their strengths are added.

• Their sum divided by two is the total force.

According to Newton's 3rd Law of Motion, the strength of a reaction force is _______ the strength of the action force.

• half of

• double

• perpendicular to

• equal to

True of False? Mass and air resistance affect the gravitational attraction between objects?

• True

• False

The greater the mass of an object,

• the easier the object starts moving.

• the more volume it takes up.

• the more balanced it it.

• the greater its inertia.

When the only force acting on a falling object is air resistance, the object is said to be in free fall.

• True

• False, gravity

• False, inertia

• False, weight

The force required to accelerate 1 kilogram of mass at one meter per second per second (kg*m/s²) is one _______

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

• attract each other.

• repel each other.

• combine to provide a balanced force.

• create friction.