As light travels through a medium, it moves in a straight line path,but when light passes from one medium into another medium, the light path bends,Refraction takes place.
The correct answer would be B. A virus is living BUT however it does NOT have all of the 7 characteristics of life.
Hope that helped ^^
The answer is definitely C.) their molecules move at the same average speed
A single fixed pulley can be used to raise or lower lightweight objects.
Option b
<u>Explanation:</u>
A pulley is a simple machine tool which is used to make lifting or lowering tasks easy. A single fixed pulley is a system involving only one pulley fixed on a constant rigid support with a rope wrapped around the wheel. Such a system can be used only to change the direction of applied force in raising or lowering small, lightweight objects which need minimal work force.
A single fixed pulley system helps only in redirecting the applied force direction by using a rope and wheel assembly. The work done in such a case remains the same and hence it is not preferred to use it in lifting heavy objects. Neither is the required force reduced in case of a single fixed pulley system. A movable pulley helps in achieving (A) and (C).
