Forces Review

What is the unit for magnitude?

Newtons

What is net force?

The combination of all forces acting on an object.

What is friction?

The contact force that acts to resist sliding between two touching surfaces.

What is static friction?

The force between two surfaces in contact that keeps them from sliding when a force is applied.

Give an example of compression force

The force exerted on a squeezed rubber ball.

Give an example of tension force

The force exerted on a stretched rubber band.

What is normal force?

The force that always acts perpendicular to the surface of an object.

What is sliding friction?

The force that opposes the motion of two surfaces in contact that are sliding past each other.

What must happen when a resting object is acted on by an unbalanced force?

The object will accelerate in the direction of the unbalanced force.

What is inertia?

The tendency of an object to resist a change in its motion.

What is noncontact force?

The type of force exerted on one object by another when the object are not touching.

What is contact force

The type of force that is only exerted when two objects are touching.

State Newton's Third Law of Motion

When one object exerts a force on a second object, the second object exerts an equal force in the opposite direction on the first object.

What are unbalanced forces?

When the net force of an object is not zero.

What are balanced forces?

When the net force of an object is zero.

Is force a vector?

Yes

Is weight a force?

Yes

One of the forces in a force pair are called ________ and ___________ forces.

action and reaction forces,

The forces that two objects exert on each other are called

force pairs

When an object changes speed or direction

its velocity changes, and the object is accelerating.

An object's speed will increase when a net force acts in the

same direction as the object's motion.

The forces in a force are equal in ________ and opposite in ____________

size and direction

Unbalanced forces can cause an object to

speed up, slow down, or change direction.

When the net force is zero,

the acceleration is zero

When the acceleration is zero,

the velocity is constant

What is centripetal force?

A force that causes an object to move in a circular path.

What are elastic forces?

A material that is stretched or compressed.

What is weight?

A measure of the gravitational force on an object.

What is a force

A push or a pull acting on an object

State the Universal Law of Gravitation

All objects in the universe are attracted to each other. According to the law of universal gravitation, the force of attraction between two objects depends on their masses and the distance between them.

What is gravity?

An attractive force between all objects that have mass.

What must happen when an object's speed or direction changes?

An unbalanced force must be acting on the object

A ball tied to a string and swung in a circle is an example of

Circular Motion

Name all the possible formulas for Newton's Second Law of Motion

F=m * a M=F/a A= F/m

State the formulas in words

F=m*a- Force is equal to mass times the acceleration M=F/a- Mass is equal to the force divided by the acceleration. A=F/m- Acceleration is equal to the force divided by the mass.

State Newton's First Law of Motion

If the net force on an object is zero, an object at rest remains at rest, or, if the object is moving, it continues to move in a straight line with constant speed.