Question

calculate the work done in increasing the velocity of a bus from 54km/h to 90km/h,if it's mass is 2000 kg​

Answer 1

you can take mass as 2000kg and solve it by using this formula

Explanation:

Initial Velocity, u=54km/hr=15m/s

Final velocity , v=72km/hr=20m/s

Mass =1500kg

Initial kinetic energy

2

1

mu

2

⇒

2

1

1500×15×15=168750J

Final kinetic energy

2

1

mv

2

⇒

2

1

1500×20×20=300000J

So, change in kinetic energy = work done=300000−168750=131250J