Physics 2007 JAMB Past Questions - Question 41: A boy drags a bag of rice along a smooth horizontal floor with a force of 2 N applied at an angle of 60 to the floor. The work done after a distance of 3 m is

Correct Answer

D

Explanation

To find the work done by the boy when dragging the bag of rice, you can use the formula for work:

Work (W) = Force (F) × Distance (d) × cos(θ),

where:
- W is the work done,
- F is the force applied,
- d is the distance over which the force is applied,
- θ is the angle between the force and the direction of motion.

In this case, the force applied is 2 N, the distance is 3 m, and the angle θ is 60 degrees. However, you need to make sure the angle is in radians, so you'll need to convert it from degrees to radians:

θ (in radians) = 60 degrees × (π radians / 180 degrees) ≈ 1.047 radians.

Now, you can calculate the work done:

W = 2 N × 3 m × cos(1.047 radians).

To find the value of cos(1.047 radians), you can use a calculator. Once you find the value, multiply it by 2 N and 3 m to get the work done.

W ≈ 2 N × 3 m × cos(1.047 radians)

Calculate cos(1.047 radians) using a calculator:

cos(1.047 radians) ≈ 0.5 (approximately).

Now, calculate the work done:

W ≈ 2 N × 3 m × 0.5
W ≈ 3 N·m (Joules)

So, the work done by the boy when dragging the bag of rice for a distance of 3 meters is approximately 3 Joules.