Question

Car questions 1)A car with the mass of 200 kg moves at a speed of 2.00 m/s. If the car doubles its speed to 4.00 m/s then how much work was done on the car? A) 1200 JB) 100 JC) 400000 JD) 200 JE)1.00 J

Answer 1

A. 1200 J

Step-by-step explanation

Given:

• The mass of the car, m = 200 kg

,

• The initial speed of the car, v₀ = 2.00 m/s

,

• The final speed of the car, v = 4.00 m/s

Unknown:

• The work done to the car, W

By the work-energy theorem, "the work done on an object by a net force equals the change in kinetic energy of the object". This means that the work done on the car is equal to the kinetic energy it received to speed up from 2 m/s to 4 m/s,

`W=\Delta KE=(1)/(2)\cdot m\cdot(v^2-v^2_o)`

Replace with the given values,

`W=(1)/(2)\cdot200kg\cdot(4^2-2^2)m^2/s^2=1200J`

Hence, the work done on the car was 1200 Joules.