Two 5 kg blobs of putty hurtle toward each other at the startling speed of 1 100 km s . After collision, they stick together. Determine how much mechanical ene

Question

 Two
5 kg
blobs of putty hurtle toward each other at the startling speed of
1
100 km s
. After
collision, they stick together. Determine how much mechanical energy is lost from the
system

Answer 1

By conservation of momentum, since the blobs are headed in opposite directions and have the same mass, the total momentum is zero, and will remain so.  Once stuck together, they will be at rest.  So they have zero mechanical (Kinetic) energy after colliding.  The amount lost is then the amount they started with.  For each blob, that is 1/2 mv².  

KE = 1/2 (5 kg)(1,100,000 m/s)² = 3,025,000,000,000 J.

 

For the two together, 6.05 x 10¹² J was loast.