Classify the following situations into contact and non-contact forces. (a) Applying brakes in a vehicle
(b) a coconut falling from a coconut tree
(c ) the planets revolving around the sun
(d) a ball is rolling on ground.

If forces acting on an object are unbalanced. true or false

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?

Alandscaper is shopping for landscaping materials. she wants to use materials through which water flows easily. which materials should she choose? check all that apply. clay gravel granite rocks with cracks loosely packed soil