Dynamics definitions

Question 1

Mass

Answer 1

Intrinsic property of a body which resists change in motion

Question 2

Inertia

Answer 2

A body’s reluctance to start moving, or to change its motion once it has started

Question 3

Weight

Answer 3

Force experienced by a mass in a gravitational field

Question 4

Momentum

Answer 4

The product of its mass and velocity

Question 5

Impulse

Answer 5

The product of a force acting on an object and the time for which the force acts on

Question 6

Force

Answer 6

Any action that causes a change in physical state or state of motion of the body

Question 7

Newton’s first law

Answer 7

A body continues in its state of rest or uniform motion in a straight line, unless a resultant external force acts on it

Question 8

Newton’s second law

Answer 8

The rate of change of momentum of a body is proportional to the resultant force acting on it and occurs in the direction of the force

Question 9

Newton’s third law

Answer 9

If a body A exerts a force on body B, then body B exerts an equal and opposite force on body A

Question 10

Linear momentum

Answer 10

The product of mass and velocity of the particle

Question 11

Principle of conservation of linear momentum

Answer 11

When bodies in a system interact, the total momentum of the system remains constant, provided no net external force acts on it

Question 12

Head on

Answer 12

The velocities of the bodies before and after collision are along the line joining their centre of masses

Question 13

Elastic Collision

Answer 13

Total KE before and after the collision is constant