Answer:
key points:1.momentum and impulse
2.condition for conservation of momentum and why
3.how to solve collision problems
4.centre of mass
Explanation:
momentum is a vector
force of a tennis ball
for a top player,a tennis ball may leave the racket on the with a speed of 55m/s(about 120mi/h).if the ball has a mass of 0.060kg and is in contact with the racket for about 4ms(4×10)s.estimate the average force on the ball
Answer:

Explanation:
Given that

As both charges are negative so there exist force of repulsion in direction as shown in figure.

Angle at which force F12 is acting is



Force exerted on charge -2e is equal in magnitude to F12 but is in opposite direction


Answer: 
Explanation:
Given
At an elevation of
, spacecraft is dropping vertically at a speed of 
Final velocity of the spacecraft is 
using equation of motion i.e. 
Insert the values

Therefore, magnitude of acceleration is
.
Answer:
C) three times slow than on earth
I think analog but I could be wrong