Physics - Unit 4

Which of the following is true about forces

All of these are true

(they can be exerted by objects in physical contact)

(they can be exerted by objects not in physical contact)

(they can be exerted through both short and long distances)

An action force and its reaction force

Are equal in magnitude and act in opposite directions

For an object at rest on a horizontal surface, the normal force will be

Equal to the magnitude of Fg-

Coeficient of static fiction is expressed

Without units

Newton's second law can best be described by

F = ma

Kinetic friction

None of these

(acts in the same direction as the motion of an object)

(has a greater magnitude than static friction)

(holds an object at rest)

The normal force acting on an object will always

Act in a direction perpendicular to the surface

Which of the following is NOT an example of a field force

A push

Inertia can best be defined as

Resisting a change in motion

Force is measured in

Newtons

The resistive force that keeps objects at rest is

Static friction

Which of Newton's Laws states that an object wants to maintain it current state of motion

1st

The magnitude of elastic force is proportional to

Distortion

The upward force exerted by a fluid is called

Buoyant force

Archimedes' principle states that the buoyant force acting on an object is equal to

The weight of the fluid displaced

Which of the following is NOT one of the four fundamental forces

Elastic

During a collision

Total momentum will be conserved

The force applied by an airbag to slow down a person can be decreased by

Increasing the time over which the force is applied

A change in momentum is an

Impulse

Which of the following is NOT a result of gravitational forces

Dense nucleus in an atom