A0.50 kg billard ball moving at 1.5 m/s strikes a second 0.50 kg billiard ball which is at rest on the table. if the first ball slows down to a speed of 0.10 m/s, then what is the speed of the second ball ? explain.

velocity of second billiard after collision = 1.4 m/sec  

Explanation:

We have mass of billiard let

Velocity of billiard let

Mass of second second billiard let

Velocity of second billiard before collision 0 m/sec  billiard

Velocity of first billiard after collision  0.1 m/sec

Now according conservation of momentum

Momentum before collision and after collision will be same

So momentum before collision = momentum after collision

So velocity of second billiard after collision = 1.4 m/sec  

kepler used the data from tycho blahe (his mentor) to construct the laws of planetary motion.