Question

76. A man is instructed to carry a package from the base camp at B to summit A of a hill at a height of 1200 metres. The man weighs 800 N and the package weighs 200 N. If g = 10 m/s², (1) how much work does man do against gravity ? what is the potential energy of the package at A if it is assumed to be zero at B ?

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Answer 1

The work done against gravity is 1000 J. The potential energy of the package at point A is 1200 J.

Step-by-step explanation:

To calculate the work done against gravity, you can use the formula:

Work = force x distance x cosine(angle)

In this case, the force is the weight of the man and the package, which is (800 N + 200 N) = 1000 N. The distance is the height of the hill, which is 1200 meters. The angle can be considered as 0 degrees since the hill is vertical.

Therefore, the work done against gravity is:

Work = 1000 N x 1200 m x cos(0°) = 1000 J

The potential energy of the package at point A is 1200 J, which is equal to the work done against gravity.

Since potential energy is the energy an object possesses due to its position, the potential energy of the package at point B is considered to be zero.