Question

What is the work done in increasing the velocity of a car from 30km/h to 60km/h, if the mass of the car is 1500kg? Write your answer in s.I. Unit.

Answer 1

Here we know that by the energy conservation law work done is equal to the increase in the kinetic every of the car.
Hence w = 1/2m v^2 - 1/2 mu^2
W = 1/2*1500(( 60^2-30^2)(1000/3600) ^2
W = 156250 j

Answer 2

[tex] \pink{answer}

Initial velocity u=30 km/h=30×

18

5

=

3

25

m/s

Final velocity v=60 km/h=60×

18

5

=

3

50

m/s

Mass m=1500 kg

Work done W=

2

1

mv

2

−

2

1

mu

2

⟹ W=

2

m

(v

2

−u

2

)=

2

1500

×((

3

50

)

2

−(

3

25

)

2 )=156187 J