Billiard ball A, mass 0.17 kg, is moving due east with a velocity of 4.0 m/s. It strikes stationary billiard ball B, which has the same mass. After the collision, ball A moves
at an angle of 30° north of east with a velocity of 3.5 m/s. Ball B moves at an
angle of 60° south of east. What is the speed of ball B?
a
2 m/s
b
8 m/s
С
10 m/s
d
5 m/s

Explain vector addition, triangle method and parallelogram method

A23 kg log of wood begins from rest, 300 m up a sluice (a water track used to transport logs, think of it as an inclined plane with negligible friction) inclined at 20° to the horizontal. after it reaches the flat waterway at the bottom it collides elastically with a 100 kg block of wood initially at rest near the base of the incline. (a) how long does it take the 23 kg log to travel down the incline? (b) what is the speed of the 23 kg log at the bottom of the incline? (c) what are the velocities of both blocks of wood after the collision? (d) what is the total kinetic energy before the collision? (e) what is the kinetic energy of the 23 kg log after the collision? (f) what is the kinetic energy of the 100 kg block of wood after the collision? (g) what is the total kinetic energy after the collision? (h) compare the total initial and total final kinetic energies. is this consistent with what you would expect for elastic collisions? explain!

What are atoms of the same element with varying number of neutrons