Question

Find the work done when a 25 kg weight is (1)lifted to a vertical height of 2.0 m from the ground (2) carried to the same place by pushing it up an inclined plane making an angle of 30 degree with the ground .

Answer 1

Answer:  1) W= 490J

2)  W= 424.34J

given: h=2m

           m=25kg

           g=9.8m/s²

to find: work done in different cases:

formula used -   W= mgh

1) W= mgh=25*9.8*2

=490J

2) W= mgh cosΘ  = 25*2*9.8* cos 30°

490*√3/2  ⇒ 424.34J