Dynamics

Question 1

Define mass

Answer 1

It is the property of an object that resists change in motion.

Question 2

Define inertia

Answer 2

Inertia of an object is the tendency of that object to resist change in motion.
The more the mass, the greater the inertia.

Question 3

State Newton’s 1st Law of Motion

Answer 3

An object will remain at rest or keep moving with constant velocity unless acted upon by resultant external force.

Question 4

State Newton’s 2nd Law of Motion

Answer 4

The resultant force acting on an object is directly proportional to the rate of change of momentum. The resultant force and the change in momentum are in the same direction.
∆p = mv-mu
F = ma

Question 5

Define force

Answer 5

It is the rate of change of momentum.
F = (mv -mu)/ t

Question 6

State Newton’s 3rd Law of Motion

Answer 6

If body A exerts a force on body B, then body B will exert a force on body B of equal magnitude but in opposite direction.

Question 7

What are the characteristics of Newton’s 3rd law pair forces?

Answer 7

• They act on two different objects
• They are equal in size
• They are opposite in direction
• The are forces of the sa.e type
• The act along the same line and for the same time

Question 8

State the principle of conservation of momentum

Answer 8

The total momentum before collision equals the total momentum after collision, for a closed system, in any direction.