(1.25P-1.29P)- N3L, Momentum, Mass, Velocity, Force

What is momentum?

The vector quantity of motion that an object has.

What causes the momentum of an object to change?

Acceleration

Change in direction

Change in mass

State the equation + units for momentum.

momentum =

p =

mass x velocity

mv

kg m/s = kg x m/s

How does momentum affect safety measures implemented?

force = rate of change in momentum

Therefore, force of impact can be decreased by increasing contact time over which the collision occurs.

What are some safety features in vehicles and why do they work?

• Crumple zones

• Seat belts

• Airbags

  Designed to absorb energy by changing shape and increasing time which reduces force.

What is the principle of conservation of momentum?

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

What is a closed system?

A system in which the energy is constant and there are no external forces.

State the equation for force using momentum.

Force =

change in momentum / time taken

(mv - mu) / t

What is Newton’s Third Law?

If a object A exerts a force on object B, B exerts a force on A that is equal in magnitude and opposite in direction.

State Newton’s 3 laws.

Objects at rest will remain at rest, or move with constant velocity unless acted upon by a resultant force.

The rate of change of velocity of an object is proportional to the force acting on it.

If a object A exerts a force on object B, B exerts a force on A that is equal in magnitude and opposite in direction.