Question

Certain force acting on a 40kg mass changes its velocity from 30m/s to 50m/s. Calculate the work done by the force.

Answer 1

According to work energy theoram-

$\boxed{\red{Work\:done\:is\:equal\:to\:change\:in\:Kinetic\:Energy}}$

By using boxed one-

$work \: done = \frac{1}{2} m {v}^{2} - \frac{1}{2} m {u}^{2} \\ \frac{1}{2} m( {v}^{2} - {u}^{2} ) \\ \frac{1}{2} 40( {50}^{2} - {30}^{2} ) \\ 20(2500 - 900) \\ 1600 \times 20joules \\ 32 \times {10}^{3} joules$

Answer 2

Answer:

32000J

Explanation:

work done =change in kinetic energy

work done=½mv²-½mv²

=½m (v² - u²)

=½40(50² -30²)

=½20(2500-900)

=20×1600

=32000J