Question

28. A car, 100 kg mass, is moving with 10 m/sec speed goes to 80 m/sec. in 20 seconds- Calculate the power of the car in horse power- 1600 HP 1000 HP 40.22 HP 20.11 HP

Answer 1

Power = 20.11 HP

Step-by-step explanation:

given data

mass m = 100 kg

speed v1 = 10 m/s

speed v2 = 80 m/s

time t = 20 s

to find out

Calculate the power of the car

solution

change in kinetic energy is express as

change in KE = 0.5 ×m×v² = work done

change in KE = 0.5 ×100× (80² - 10²)

change in KE = 315000 J

and

we know power =
`(work done)/(time)`

power =
`(315000)/(20)`

power = 15750 W

so now for power in HP we divide the power 746 so we get

power =
`(15750)/(746)`

power = 21.11 HP

so nearest value is 20.11 HP

so correct option is 20.11 HP