3 Dynamics

Question 1

Newton’s First Law of Motion

Answer 1

An object will remain in its state of motion/rest unless an external resultant force acts on it

Question 2

Inertia

Answer 2

Reluctance of a body to change its state of rest/motion

Question 3

Mass

Answer 3

A measure of a body’s resistance to change in velocity

Question 4

Weight

Answer 4

Force acting on a mass due to a gravitational field
W = mg

Question 5

Newton’s Second Law of Motion

Answer 5

Rate of change of momentum is directly proportional to the resultant force acting on the body and occurs in the direction of the resultant force

Question 6

Linear momentum

Answer 6

Product of mass and velocity
Linear momentum is in the same direction as velocity
p = mv

Question 7

Force

Answer 7

Rate of change of momentum
F = m(Δv/Δt) = ma

Question 8

Newton’s Third Law of Motion

Answer 8

If a force is exerted from one body to another, the other body will exert a force of the same type that is equal in magnitude and opposite direction onto the first body

Question 9

Impulse

Answer 9

The product of an average force acting on an object and the time for which the force acts
Impulse = FΔt = change in momentum
Area under F-t graph = impulse

Question 10

Principle of Conservation of Linear Momentum

Answer 10

Total momentum of a system remains constant provided no external force acts on the system
m1 u1 + m2 u2 = m1 v1 + m2 v2

Question 11

Elastic collison

Answer 11

A collision which kinetic energy is conserved
u1 - u2 = v2 - v1

Question 12

Inelastic collision

Answer 12

A collision which kinetic energy is not conserved

Question 13

Weightlessness

Answer 13

No contact forces acting on an object