High School

A coolie lifts a luggage of 15 kg from the ground and puts it on his head 1.5 m above the ground. Calculate the work done by him on the luggage.

a) 147 J
b) 22.5 J
c) 1.5 J
d) 0 J

Answer :

Final answer:

To calculate the work done by the coolie, the weight of the luggage is multiplied by the gravitational acceleration to get the force, and then this force is multiplied by the displacement. The correct answer is 147 J, which is the product of the luggage's weight (147 N) and the height (1.5 m).

Explanation:

The student asked to calculate the work done by a coolie who lifts a luggage weighing 15 kg to a height of 1.5 meters above the ground. In physics, the work done by a force is calculated as the product of the force and the displacement in the direction of the force. Since the coolie is lifting the luggage vertically, the force is equal to the weight of the luggage which is the product of the mass and gravitational acceleration (9.8 m/s2). Thus, the work done can be calculated using the formula:

Work done (W) = Force (F) × Displacement (s)

First, we calculate the weight:

Weight (F) = Mass (m) × Gravitational acceleration (g)

Weight = 15 kg × 9.8 m/s2 = 147 N

Now we calculate the work done:

W = 147 N × 1.5 m = 220.5 J

Therefore, the correct answer is a) 147 J, as the work done by the coolie on the luggage is 147 joules.