Question

Let us assume that you have lifted a suitcase and kept it on a table. On which of the following does the work done by you depend or not depend? Why? 

a) The path taken by the suitcase 

b) The time taken by you in doing so 

c) The weight of the suitcase 

d) Your weight

Answer 1

We know that P.E. = mgh 

a) The work done by you does not depend on the path taken by the suitcase, because the height from the ground to the top of the table is fixed in this case, (h constant) 

b) The work done by you does not depend the time taken, in doing so, because the work done is same. If you take less time your power will be more otherwise the power is less.

c) The work done by you depends on the weight of the suitcase. As the weight of the suitcase increases, the work done will also increase (See the formula P.E. = mgh). 

d) The work done by you depends on your weight, we know that a person with more weight can Mft the suitcase easily.