Newton’s Laws

Question 1

normal force (N)

Answer 1

The force or the components of a force which a surface exerts on an object with which it is in contact, and which is perpendicular to the surface.

Question 2

frictional force (f)

Answer 2

The force that opposes the motion of an object and which acts parallel to the surface.

Question 3

static frictional force (fs)

Answer 3

The force that opposes the tendency of motion of a stationary object relative to a surface. 

Question 4

Kinetic frictional force (fk)

Answer 4

The force that opposes the motion of a moving object relative to the surface. 

Question 5

Newton’s first law of motion

Answer 5

A body will remain in its state of rest or motion at constant velocity unless a non-zero resultant/net force acts on it. 

Question 6

Newton’s second law of motion

Answer 6

When a net force acts on an object, the object will accelerate in the direction of the force and the acceleration is directly proportional to the force and inversely proportional to the mass of the object. 

Question 7

Newton’s third law of motion

Answer 7

When object A exerts a force on object B, object B simultaneously exerts an oppositely directed force of equal magnitude on object A. 

Question 8

Newton’s law of universal gravitation

Answer 8

Each body in the universe attracts every other body with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres. 

Question 9

Weight (w)

Answer 9

The gravitational force that the Earth exerts on any object on or near the surface.