Slides in this set
As long as no external forces are on the object
involved, the momentum stays the same in
explosions and collisions. This is called
conservation of momentum.
· Total momentum before = Total momentum
afterwards in a collision.…read more
In a explosion, there is an internal impulse which sends a
different part of the system or object into different directions.
All these little parts make many different vectors. If the sum of
all these vectors add up, to find the final momentum, then it
should also equal to the initial momentum, so momentum
before = momentum after.…read more
Safety features in vehicles
· When there is a car crash, the car, passengers, decelerate rapidly. They
experience great forces because of the change in momentum, which can
cause injury. If the time taken for the change in momentum on the body
is increased, the forces on the body are reduced too. Seat belts and
crumple zones are designed to reduce the forces on the body if there is a
· Seat belts stop you tumbling around inside the car if there is a collision.
However, they are designed to stretch a bit in a collision. This increases
the time taken for the body's momentum to reach zero, so reduces the
forces on it.
· Air bags increase the time taken for the head's momentum to reach zero,
so reduce the forces on it. They also act a soft cushion and prevent cuts.…read more