# Momentum Flashcards

What is the equation for momentum?

Momentum = Mass x Velocity

p = m x v

What is the unit for momentum?

Kilogram metres/second

kg m/s

What does the law of conservation of momentum state?

In a closed system, the total momentum before an event is equal to the total momentum after the event.

Does momentum have a direction?

Yes

What does a minus sign before a momentum tell us?

That the momentum is in the opposite direction (to another momentum).

When two objects push apart, they move…

With equal and opposite momentum.

In an explosion, what can be said about the two momentums?

They add up to zero.

What is the equation for impact force?

Force = Change in momentum / Time

What effect does impact time have on the force?

The longer the impact time, the weaker the force.

How do seat belts and air bags help keep the passenger safe?

They increase impact time and spread the force over a larger area.

How do crumple zones keep passengers safe?

They ‘crumple’, increasing the impact time and therefore reducing force.