The answer is letter c.
The explanation behind this is when human consumes a plant
or when a human being eats an animal that ate a plant. The chemical energy kept
in the plant (or animal) cells is progressed into the cells of the human's
body. All of the body progressions, like ingestion, breathing, pumping blood, are
driven by cells changing the kept chemical energy into heat and work, in a procedure
called respiration. In the muscle cells of the human (or any animal), the
chemical energy is converted into mechanical work and heat. The muscle pacts,
the legs thrust, and the body jumps into the air.
We don't even need to know how many pulses were produced
in those 3 seconds.
The beginning of the first pulse took 3 seconds to travel
45 centimeters from the generator.
Its speed is (45 cm) / (3 sec) = 15 cm/sec.
A). nuclear
No. There were batteries long long before we learned
how to use nuclear energy. Also, there is no danger of
exposure to radioactivity when you're working with a battery.
b). mechanical
No. A battery has no moving parts.
c). gravitational
No. No matter how high you take a battery in an airplane, or
how far you lower it into a mine-shaft, its characteristics don't
change. In fact, batteries even work on things that are in orbit.
d). chemical
Bingo.
