Momentum and Collision

Question 1

What is momentum?

Answer 1

product of mass and velocity
p = mv

Question 2

What is the relationship of p with KE?

Answer 2

KE = p2/2m

Question 3

What is Newton’s second law of momentum?

Answer 3

Net force = delta p/delta t

Question 4

What is impulse?

Answer 4

I = F delta t = delta p = mvf - mvi

Question 5

What is average force?

Answer 5

delta p = Fav delta t

Question 6

What is law of conservation of momentum?

Answer 6

m1v1i + m2v2i = m1v1f + m2v2f

Question 7

What is inelastic collision?

Answer 7

Momentum is conserved but kinetic energy is not.

Question 8

Why is kinetic energy not conserved in inelastic collision?

Answer 8

Some of the kinetic energy is converted into internal energy, sound energy and work needed to permanently deform objects involved.

Question 9

What is perfectly inelastic collision?

Answer 9

When two objects collide and stick together. Same final velocities.
m1v1i + m2v2i = (m1 + m2)vf

Question 10

What is elastic collisions?

Answer 10

Both kinetic energy and momentum is conserved.

Question 11

What are the formulas for elastic collision?

Answer 11

m1v1i + m2v2i = m1v1f + m2v2f
1/2m1v1i2 + 1/2m2v2i2 = 1/2m1v1f2 + 1/2m2v2f2
v1i - v2i = -(v1f - v2f)