Question

At any instant of time t, the displacement of any particle is given by 2t – 1 (SI unit) under the influence of force of 5N. The value of instantaneous power is (in SI unit):

• A. 10
• B. 5
• C. 7
• D. 6

Answer 1

Answer: (A)

10

Answer 2

The velocity is given by the derivative of displacement with respect to time:
$v = \frac{dx}{dt} = \frac{d(2t - 1)}{dt} = 2 \, m/s$.
The instantaneous power is calculated as:
$P = F \cdot v = 5 \times 2 = 10 \, \text{W}$.