Question

what work is said to be done to increase the velocity of a car from 15km/h,if the mass of the car is 1000kg??​

Answer 1

Answer:

Given:-

u=15km/h

v=30km/h

Mass=1000 kg

W=?

W=K.E.=

2

1

m(v

2

−u

2

)

=

2

1

×1000×((30)

2

−(15)

2

)

=

2

1

×1000(900−225)

=

2

1

×1000(675)

K.E.=337500J

∴ Work done =337500 Joule.

Answer 2

Answer:

I think your question is wrong:-

what work is said to be done to increase the velocity of the car from 15 kilometre per hour to 30 km per hour if mass of car is 1000 kg?

It is right question

m = 1000 kg  

u = 15 km/h = 50/12 m/s

v = 30 km/h = 100/12 m/s

Work done = change in K.E.

K.E. = 1/2 mv² = 1/2 * 1000 * 50/12 * 50/12 = 8680.5 J

K.E. = 1/2 mv² = 1/2 * 1000 * 100/12 * 100/12 = 34722.2 J

34722.2 - 8680.5 = 26041.7 J

Hence work done = 26041.7 J

Explanation: