Physics Force and Friction

According to Newton's first law of motion, an object at rest will remain at rest and an object in motion will continue moving at a constant velocity unless acted upon by an external force. True or False?

• False

• Only objects in space follow this law

• An object at rest will eventually start moving

• True

Which of Newton's laws of motion states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass?

• Newton's third law of motion

• Newton's second law of motion

• Newton's first law of motion

• Newton's law of universal gravitation

Frictional force always acts in the opposite direction to the motion of an object. True or False?

• True

• Frictional force acts in the same direction as the motion of an object

• Frictional force does not exist

• False

What is the SI unit of force?

• Kilogram

• Meter

• Second

• Newton

The normal force is the force exerted by a surface to support the weight of an object resting on it. True or False?

• False

• Partially true

• Not applicable

• True

Which of Newton's laws of motion states that for every action, there is an equal and opposite reaction?

• Newton's second law of motion

• Newton's law of universal gravitation

• Newton's third law of motion

• Newton's first law of motion

The force required to keep an object moving with a constant velocity is called ________.

• net force

• gravity

• acceleration

• friction

The force of friction depends on the weight of the object. True or False?

• False

• Friction is not affected by weight

• Weight has no impact on friction

• True

What is the formula to calculate the force of friction?

• force of friction = coefficient of friction * normal force

• force of friction = mass * acceleration

• force of friction = velocity * time

• force of friction = weight * distance

The normal force is always equal to the weight of an object. True or False?

• False

• True

• Sometimes

• Depends on the object