Which semiconductors are preferred to make led and why?.

A14 kg rock starting from rest free falls through a distance of 5.0 m with no air resistance. find the momentum change of the rock caused by its fall and the resulting change in the magnitude of earths velocity. earth mass is 6.0 * 10^24 kg. show your work assuming the rock earth system is closed.

What ions are formed when hcl dissolves in water?

Match each type of lever with the correct diagram. 1. first-class 2. third-class 3. second-class