Question

A truck weighing 1000 kgf changes its speed from tran
36 km/hr to 72 km/ hr in 2 minutes. Calculate -
the work done by the engine, and (ii) its power.
(= 10 ms)​

Answer 1

Answer:

Explanation:

U = 36 km/h = 36 x 1000m/3600s = 10m/s

AND V= 72km/h=72x1000m/3600s=20m/s

mass of truck=1000KG now

(i)work done=

w= 1/2 x mass x (v²-u²)

  =1/2 x 1000 x (20²-10²)

  =500 x (400-300)

  =500 x 300

  =150000J

(ii) power

   power = work done/ time taken

              =150000/120s

              =1250 W