helicopter of mass 3000kg rises vertically at a constant speed of 25m/s if the acceleration due to gravity is10m/s2 ,determine the resultant force working on the helicopter

Draw the scales of a msg showing 2.86mm for a 50 divisions msg

Describe how the oil patch is formed in an oil drop experiment. 

What is the essence of an oil molecule in hydraulic machines?

Give a reason why mass of a body is constant everywhere.

Suggest two methods of improving the efficiency of a machine.