C. when the circuit is closed
Answer:

Explanation:
Project mass m=3.8 kg
Initial speed vi= 0m/s
Final speed vf= 9.3×10³ m/s
Force F=9.3×10⁵N
To find
Time t
Solution
From Newtons second law we know that
∑F=ma
Where m is mass
a is acceleration
We can write this equation as
∑F=m(Δv/Δt)

Rearrange this equation to find time t
So

Substitute the given values
If "0.3 minute" is correct, then it's 9,543,272 Joules.
If it's supposed to say "0.3 SECOND", then the KE is 2,651 Joules.
Fist one is a cylinder
the second, i believe is a sphere
the third is a rectangular prism
and the last is the same as the first, a cylinder
Almost all of the energy on Earth comes from the Sun
The energy in fossil fuels originally came from the Sun
Plants convert the energy
Explanation:
The sun is the ultimate source of energy on earth and even the whole of the solar system. The sun drives and powers all external processes on earth. It produces its energy from the nuclear fusion of lighter nuclei into heavier ones.
- Almost all of the energy on earth comes from the sun. A few component of the energy on the surface comes from the internal heat engine.
- The energy of fossil fuels originally came from the sun. This is because, plants stores the energy in the process of photosynthesis. When they die and the energy is not released, the energy is stored as fossil fuels.
- Plants in the process of photosynthesis converts the energy. Here green plants combines carbon dioxide and water in the presence of sunlight.
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