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

Power = 20.11 HP

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 =

power =

power = 15750 W

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

power =

power = 21.11 HP

so nearest value is 20.11 HP

so correct option is 20.11 HP

d. new methods of assembly are introduced.

explanation:

this allows for the goods to be made on a larger scale. not faster because now it is shown to be made better, hence the greater productivity in the question. it is calling for something new to be introduced.