Question

A car weighing 500 kg moving anainst a resistance of 500 N, accelerates from rest to 20 m//s in 100m (g = 10m//s^2). The work done by the engine of the car is :

Answer 1

Answer:

150000joules

Explanation:

x be the apparent force (ignoring the resistant force)

therefore,total force=(x + 500)N

u= 0 m/s

v= 20 m/s

let time taken be t

therefore a = (v - u)/t

=20/t

s = 100 m

applying the equation v2 - u2= 2as

20^2=2×20×100÷t

t=10 s

therefore a=20÷10m/s^2 =2 m/s^2

therefore x = 500×2 N (as f = ma)

= 1000 N

total force = 500N + 1000N = 1500N

so, total work done = 1500×100 Nm

=150000 joules

Hope it helped you.