Forces, Momentum and Moments

Question 1

Momentum formula

Answer 1

p(kgms-1) = m(kg) x v(ms-1)

Question 2

Impulse formula

Answer 2

= dP

mv - mu

Question 3

Force and Momentum Linkage

Answer 3

F = dP/t

Question 4

Conversation of Momentum

Answer 4

In a closed system (no external forces acting on objects), the total momentum of a system remains constant
Total initial = Total final

Question 5

How do safety features reduce impact force

Answer 5

Increase contact time during collision (F = dP/t, as t increases F decreases)
Absorbs energy from impact
Reduces force and risk of injury

Question 6

Newton’s Third Law

Answer 6

For every action, there is an equal and opposite reaction
If object A exerts a force on object B, object B exerts a force of the same size but in the opposite direction of an object

Question 7

Moment equation

Answer 7

M (Nm) = F(N) x d(m)
d being perpendicular distance from pivot

Question 8

Center of gravity definition

Answer 8

The point where the entire weight of an object appears to act

Question 9

Principle of Moments

Answer 9

In a system at equilibrium: Sum of clockwise moments = Sum of anticlockwise moments

Question 10

Upwards forces on a supported beam

Answer 10

The support closer to the object bears more of the load (M = Fd, force remaining constant)
The forces adjust to balance the total weight and keep the beam in equilibrium