Question

HELP PLEASE:How much work is done to increase the speed of a 2kg body from 36km / h to 72km / h?​

Answer 1

Answer:

100 joules (J).

Explanation:

Converting Units - 36 km/h = 10 m/s

                               72 km/h = 20 m/s ( 1 km/h =  5/18 m/s)

Change in speed = 20 - 10 = 10 m/s

Applying the Work-Energy theorem,

$Work done = \frac{1}{2} 2 (10)^2$

                 = 100 J.