Question

What is the work done to increase the velocity of a car 30 km/hr to 60km/hr if the mass of the car is 1500kg

Answer 1

Answer:

Given :-

The mass of car = 1500 kg

Initial velocity of the car = u = 30 km/h

= 30 × 1000 / 60 × 60 sec

= 8.33 m/s

Final velocity of the car = 60 km/h

= 60 × 1000/60×60sec

= 16.67 m/s

To Find :-

work done = ?

SOLUTION :-

According to the work energy theorem ,

change in KINETIC ENERGY is known as work done .

∆k = W

∆k = k1 - k2

INITIAL KINETIC ENERGY = K1

$k1 = \frac{1}{2}m {u}^{2} \\ = \frac{1}{2} \times 1500 \times 8.33 \times 8.33 \\ \\ = 52041.68joule$

FINAL KINETIC ENERGY = K2

$k2 = \frac{1}{2}m {v}^{2} \\ = \frac{1}{2} \times 1500 \times 16.67 \times 16.67 \\ \\ = 208416.68joule$

WORK DONE = K1 - K2

work done = ∆k

W = k1 - K2

= 208416.68 - 52041.68

= 156375 J.

____________________________

WORK DONE IS 156375 J

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