Photovoltaic cells are well known for their ability to convert solar energy (1) into electrical energy.
Answer:
false
Explanation:
every object will always have the force of gravity acting upon it.
Answer:
Work done, W = 19.6 J
Explanation:
It is given that,
Mass of the block, m = 5 kg
Speed of the block, v = 10 m/s
The coefficient of kinetic friction between the block and the rough section is 0.2
Distance covered by the block, d = 2 m
As the block passes through the rough part, some of the energy gets lost and this energy is equal to the work done by the kinetic energy.


W = 19.6 J
So, the change in the kinetic energy of the block as it passes through the rough section is 19.6 J. Hence, this is the required solution.
Sound travels through the ear via compression