Question

A truck of mass 1000kg, increases its speed from 36 km/h to 72km/h . Find the increase in its kinetic energy. Show the process

Answer 1

Mass of car m = 1000 kg

velocity = 36 km/h = 36 x 5/18 = 10 m/s

velocity = 72 km/h = 72 x 5/18 = 20 m/s 

Initial kinetic energy = ½ mv2           
                                = ½ x 1000 x (10)2                           
                               = 50000 J

Increased kinetic energy = 1/2 mv2     
                                          = ½ x 1000 x (20)2           
                                          = 200000 J

Work done = Change in kinetic energy         
                    = 200000 - 50000             
                    = 150000 J


Hope this helps!

Answer 2

Answer:

The Above answer can also be written as

= 1.5 * 10^5 Joules