You are at rest with respect to the car.
You are in motion with respect to the School.
Answer:
Part a)

Part b)

Explanation:
Part a)
If block is sliding up then net force must be zero and friction will be in opposite to the direction of motion of the block


so we have





Part b)
If block is sliding down then net force must be zero and friction will be in opposite to the direction of motion of the block


so we have





Mass per cubic metre so kg/m3. Temperature may give different results.
Nuclear fusion because atomic nuclei combine to form a heavier nucleus. Option A is correct.
<h3>What is nuclear fusion?</h3>
The process by which two or more tiny nuclei unite to generate a bigger nucleus is known as a nuclear fusion reaction.
The more energy it takes to liberate an electron from a smaller atom. This is referred to as binding energy.
As a result, when two little nuclei fuse together, there is more binding energy than when two big nuclei fuse together.
For example, the fusion of two hydrogen atoms produces more energy than the fusion of one helium atom, and surplus energy is expelled into space upon binding.
Nuclear fusion because atomic nuclei combine to form a heavier nucleus.
Hence, option A is correct.
To learn more about nuclear fusion refer to the link;
brainly.com/question/14019172
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