These energy exchanges are not changes in kinetic energy. They are changes in bonding energy between the molecules. If heat is coming into a substance during a phase change, then this energy is used to break the bonds between the molecules of the substance. The example we will use here is ice melting into water.
8 miles per hour
because if it is moving at 4 miles every half hour that means you have to multiply it by two to get it in miles per hour and we all know that 4 times 2 is 8 so it would be 8 miles per hour =)
The period of the wave would be halved
It would mean that only one side of earth would be light and the other dark all the time also we would only see the sun on one side and on the other we see the moon