Answer:
3) From 37 km/h to 47 km/h
Explanation:
Kinetic Energy: This is the energy posses by a body in motion. The Unit of kinetic energy is joules. And it is expressed mathematically as,
Ek = 1/2mv².................... Equation 1
ΔEk = 1/2m(v₂² - v₁²)...................... Equation 2
Where ΔEk = change in kinetic energy, m = mass of the body, v₁ = initial velocity, v₂ = final velocity of the body.
Note: The mass of the car is constant in both cases.
When the body accelerate from 27 kh/h to 37 km/h
ΔEk₁ = 1/2m(37²-27²)
ΔEk₁ = 1/2m(640)
ΔEk₁ = 320m J.
When The body accelerate from 37 km/h to 47 km/h
ΔEk₂ = 1/2m(37²-47²)
ΔEk₂ = 1/2m(840)
ΔEk₂ = 420m J
From the above,
ΔEk₂ > ΔEk₁.
Hence the correct option is 3) From 37 km/h to 47 km/h
