2- Momentum

Question 1

momentum

Answer 1

• measured in Ns or kgms^-1
• vector quantity (as depends on direction)
• momentum = mass * velocity
• impulse momentum = force * time

Question 2

collisions

Answer 2

• momentum is always conserved (there is a law)
• combined massvelocity before collision = combined massvelocity after
• velocity of objects heading towards each other will always be of opposite signs, because velocity is a vector

Question 3

explosions

Answer 3

• like a collision, except velocity*mass before the explosion = 0 kgms^-1
• this means the two moments have to cancel out
• can be used to calculate the speed or mass of any object in an explosion

Question 4

Newtons laws

Answer 4

1- objects in motion stay in motion unless an outside force acts on them
2- Force = Mass*acceleration (can be used to find impluse as resultant force = change in momentum/time interval)
3- all forces have a reaction force equal in magnitude and opposite in direction