Question

A lift having mass 1000kg moves upward against a frictional force of 2000N. Power given by motor is 36000W. What is the velocity of the lift?

• A. \(2 \, \text{m/s}\)
• B. \(3 \, \text{m/s}\)
• C. \(5 \, \text{m/s}\)
• D. \(6 \, \text{m/s}\)

Hint:

To calculate velocity, use the relationship between power, force, and velocity: \(P = F \times v\).

Answer 1

The Correct Option is B

The power required to lift the lift is given by the formula: \[ P = F \times v \] Where: - \(P = 36000 \, \text{W}\), - \(F = 2000 \, \text{N}\) (frictional force), - \(v\) is the velocity of the lift. Solving for \(v\): \[ v = \frac{P}{F} = \frac{36000}{2000} = 18 \, \text{m/s} \] Thus, the velocity of the lift is 3 m/s.