Question

A 1.000 kg car moves at 20 m/s, 5 seconds later the velocity of the car is 40 m/s. Calculate the work done by the car's machine.

Answer 1

M = 1000 kg
Vo = 20 m/s
t = 5 s
Vt = 40 m/s
Question : F ?

answer :
a = (Vt-Vo)/t
   = (40-20)/5
   = 20/5
   = 4 m/s²

so, the work is :
F = m x a
   = 1000 x 4
   = 4.000 N

Answer 2

Diketahui :
m = 1000 kg
vo = 20 m/s
t = 5 s
vt = 40 m/s

ditanyakan:
W = ?

jawab :
W = 1/2 m (vt²-vo²)
W = 1/2 1000 (40²-20²)
W = 500 (1600-400)
W = 500 (1200)
W = 600kJ