What is the work done to increase the velocity of a car from 30 km/h to 60 Km/h if the mass of the car is 1500kg ?

Answer

A, B

Explanation

Here, `u = 30km//h = (30xx(5)/(18))m//s = (25)/(3)m//s (1km//h = (5)/(18) m//s)`
`upsilon = 60km//h = (60xx(5)/(18))m//s= (50)/(3)m//s`
m = 1500kg
According to work-energy theorem,
`W = (1)/(2)m upsilon^2 - (1)/(2)mu^2 = (1)/(2)m(upsilon^2 - u^2)`
or `W =(1)/(2)xx1500kg[((50)/(3)m//s)^2 - ((25)/(3)m//s)^2]`
`=750kg[((2500)/(9)-(625)/(9))(m//s)^2]`
`=750kgxx208xx208.33(m//s)^2 = 156250J`