PHYSICS PLEASE HELP!!
posted by Mel on .
A tennis ball of mass= 0.058 kg and speed= 19 m/s strikes a wall at a 45 degree angle and rebounds with the same speed at 45 degrees.
What is the magnitude of the impulse given to the ball?

Only the momentum component perpendicular to the wall changed.
The change,
2M*V cos 45,
equals the impulse given 
Velocity of boat relative to the river(vbr):3 km/hr, velocity of river relative to ground(vrg) :2 km/hr. Velocity of boat relative to the ground(vbg): square root of 9+4