Power supplied to change the velocity of a car from 10m/s to 5m/s in 4sec is 100w. Find t he work done if the mass of the car is 1000kg. Find the k. E. Before and after the power is supplied to it.
Answers
Answered by
4
Power = 100 watts
u = 10 m/s
v = - 5 m/s
t = 4 sec
m = 1000 kg
Work = ?
Initial kinetic energy = ?
Final kinetic energy = ?
Work = m/2 ( v×v - u×u)(Work energy theorem )
=1000/2(5×5-(-10×-10)
= 500 (25-100)
= 500×75
=37500 J
Initial kinetic energy = m×u×u/2
=1000 ×10 ×10 /2
=100000/2
=50000 J
Final kinetic energy = m×v×v/2
=1000×-5×-5/2
=25000/2
=12500 J
Similar questions