First slide

Work

Question

A force acts on a 30g particle in such a way that the position of the particle as a function of time is given by $x = 3 t - 4 t^{2} + t^{3}$ , where x is in metres and t is in seconds. The work done (in J) during the first 4 seconds is

Moderate

Solution

$v = \frac{dx}{dt} = 3 - 8 t + 3 t^{2}$
$∴ v_{0} = 3 m / s and v_{4} = 19 m / s$
$W = \frac{1}{2} m (v_{4}^{2} - v_{0}^{2})$ (According to work energy theorem)
$= \frac{1}{2} \times 0 .03 \times (19^{2} - 3^{2}) = 5 .28 J$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App