Chapter 12 Force

The force that keeps an object moving in a circle is called what?

Centripetal force

Projectile motion is caused by what?

a combination of initial forward velocity & downward vertical force of gravity

Give an example of an action and reaction force.

a swimmer in water

When an unbalanced force acts on an object, the object -----

accelerates

When opposite poles of two magnets are brought together, the poles -----

attract

As an astronaut travels far away from earth, his weight will ------

decrease

What force is responsible for the repulsion between two positively charged particles?

electric forces

Which universal force is the weakest?

gravity

The forces acting on a falling piece of paper are -------- and --------

gravity, air resistance

The gravitational force between two objects increases as mass -------- or distance ---------

increases, decreases

The property of matter that resists changes in motion is called ---------

inertia

According to Newton's second law of motion, the acceleration of an object equals the net force acting on the object divided by the objects ------

mass

Your weight equals your ------

mass X acceleration due to gravity

The product of an objects mass and velocity is its -------

momentum

What is conserved when two objects collide in a closed system?

momentum

The SI unit of force is the what?

newton

The curved path of a ball is what?

projectile motion

What are the four different kinds of friction?

static, sliding, rolling, and fluid

Which universal force acts only on the protons and neutrons in a nucleus?

strong nuclear force

An open parachute increases air resistance of a falling sky driver by increasing the ---------

surface area

Newton's third law of motion describes -------

whenever one object exerts a force on a second object, it exerts an equal and opposite force.

When a pair of balanced forces acts on an object, the net force that results is equal to ------

zero