What causes dust particles to move with brownian motion?

Give an example of a collision in real life. use the law of conservation of energy to describe the transfer of momentum. be sure and discuss the momentum before and after the collision occurs. you will need at least 3 sentences to thoroughly answer this question.

If the work required to stretch a spring 3 ft beyond its natural length is 15 ft-lb, how much work is needed to stretch it 27 in. beyond its natural length?

Apiece of metal 75g at 110°c is dropped in a container with 500g at 20°c. the h2o if temperature is 24°c find specific heat capacity of metal