Further Mechanics

Question 1

Momentum

Answer 1

Mass x velocity (mv)
(vector) [Ns or kg m/s]

Question 2

Impulse

Answer 2

final momentum - inital momentum (I = mv - mu)
OR
force x time (I = Ft)
(vector)

Question 3

SUVAT

Answer 3

S = Distance
U = Initial Velocity
V = Final Velocity
A = Acceleration
T = Time

Question 4

Conservation of Momentum

Answer 4

m1u1 + m2u2 = m1v1 + m2v2

Question 5

Work Done

Answer 5

force x distance
(Component of force in direction of motion x distance moved in direction of force)
OR
Final K.E. - Initial K.E.
(1/2mv^2 - 1/2mu^2)
(joules)

Question 6

Work done against gravity

Answer 6

mass x acceleration due to gravity x vertical distance (mgh)
(joules)

Question 7

Kinetic Energy (K.E.)

Answer 7

1/2mv^2 (joules)

Question 8

Potential Energy (P.E.)

Answer 8

mass x acceleration due to gravity x height (mgh)

Before calculating a particle’s P.E. you must choose a ZERO LEVEL of P.E.
(joules)

Question 9

Principal of conservation of mechanical energy

Answer 9

When no external forces (other than gravity) do work on a particle during its motion, the sum of the particle’s K.E. and P.E. remains constant.
(Before = after)

Question 10

Work-energy principle

Answer 10

The change in the total energy of a particle is equal to the work done on the particle.

Question 11

Power

Answer 11

Driving force x speed (Fv)
(watts => joules/second)

Question 12

Law of restitution

Answer 12

Speed of separation of particles / speed of approach of particles 0 <= e <= 1

Question 13

Loss of K.E.

Answer 13

(1/2m1u1^2 + 1/2m2u2^2) - (1/2m1v1^2 + 1/2m2v2^2)

Question 14

Force

Answer 14

mass x acceleration
(If a = 0, then force = 0) => i.e ‘constant speed’

Question 15

Coefficient of Friction

Answer 15

friction force = mu x