The molecules making up object collide with the molecules of the other and some of the kinetic energy from a warmer object is transferred to the cooler one.
Answer:
The relative speed of 1 relative to 2 is 0.88c
Explanation:
In relativistic mechanics the relative speed between 2 objects moving in different direction is given by

Since it is given that

Applying values in the formula we get

Answer:
(1) Sure, the frequency is 1000 Hz.
Explanation:
Frequency = wave speed ÷ wave distance
wave speed = 100 m/s
wave distance = 10 cm = 10/100 = 0.1 m
Frequency = 100 ÷ 0.1 = 1000 Hz
The complete statement is
As a solid element melts, the atoms become more separated and they have less attraction for one another.
Let me explain to you how this happens. In solid phase. Its molecules are arranged in a very compact manner that is why it takes a definite shape and volume. When it is heated, the kinetic energy of the molecules increases. This is characterized by more frequent collisions. The rise in temperature causes the molecules to move rapidly by vibrating. When it reaches an amount of energy that causes the solid to change phase, this is called the latent energy. The molecules break their form and move farther away from each other until it resembles that of a liquid melting. At this point, the molecules would have lesser attraction because of the distance between them.