work in physics

Question

1.(a) How much work is done to move a 1.80 X 10³-kg Chevrolet Tahoe from rest to 35.2 m/s on a level road?



(b) If this takes place over a distance of 251 m, what is the average net force applied to the car?

Answer 1

1a.

Calculate the change in kinetic energy. That will give the work.

W = (m/2)(v₂² - v₁²)

m = 1.80 x 10³ kg

v₁ = 0 (started from rest)

v₂ = 35.2 m/s

Plug in the numbers and get W in joules.

1b.

W = FΔx ⇒

F = W / Δx

Δx = 251 m

W = result from part 1a

Plug in the numbers and get F in newtons.