How to calculate how deep an object sinks in water

A100-watt light bulb illuminates a solar cell. the electricity from the solar cell operates a water pump that delivers 1 watt of power. what is the efficiency of the system?

Explain what will happen if decomposers were apsent from a forest ecoysystem.

Avertical clean glass piezometer tube has an inside diameter of d = 1 mm and is used to measure pressure in a horizontal pipe carrying water as shown. due to pressure in the pipe, the water at 20c rises into the tube to a height h. if the water pressure in the pipe is p = 500 pa gauge, estimate the height h: (a) without considering surface tension (b) with surface tension (capillary) effects. the contact angle  can be assumed at 30 deg