Moments/momentum

Question 1

What is the momentum equation

Answer 1

momentum(p) (kgm/s)= mass(m)(kg) * velocity(v)(m/s)

Question 2

How do crumple zones work (using momentum)

Answer 2

It increases the time. The longer it takes for a change in momentum, the smaller the force. Therefore less severe injuries as the car stops slower

Question 3

How do seatbelts work (using momentum)

Answer 3

Seat belts stretch slightly, increasing the time, the longer it takes for a change in momentum, the smaller the force. Therefore reduced forces on the chest

Question 4

How do airbags work? (using momentum)

Answer 4

Slow you down gradually, so there is a longer change in momentum and a lesser force

Question 5

Conservation of momentum

Answer 5

momentum is coserved, meaning inital mass * velocity = final mass * velocity

Question 6

Force and momentum equation

Answer 6

Force (F)(N) = change in momentum (mv-mu) (kgm/s) /time (t) (s)

Question 7

Moment equation

Answer 7

Moment(Nm) = Force (n) * perpendiclar distance (m)

Question 8

Centre of gravity?

Answer 8

The point at which the weight of a body acts

Question 9

why is the force on two supports not equal when object is placed on it

Answer 9

It depends on the position, if it is closer to one support, that support will provide a greater force

Question 9

Prinicple of balanced moments

Answer 9

Total anticlockwise moments = total clockwise moments (if balanced)