Work, Power and EnergyEasy
Question
A man of mass m standing at the bottom of the staircase of height L climbs it and stands at its top
Options
A.Work done by all forces on man is equal to the rise in potential energy (mgL)
B.Work done by all forces on man is zero.
C.Work done by the gravitational force on man is mgL.
D.The reaction force from a step does not do work because the point of application of the force does not move while the force exists.
Solution
Work done by all forces include work done by man himself.
Applying work energy theorem; Wall = ᐃKE
Since man finally comes to rest ⇒Wall = 0
Work is done by a force only when point of application of force moves in the direction of force applied.
Applying work energy theorem; Wall = ᐃKE
Since man finally comes to rest ⇒Wall = 0
Work is done by a force only when point of application of force moves in the direction of force applied.
Create a free account to view solution
View Solution FreeMore Work, Power and Energy Questions
Consider a roller coaster with a circular loop. A roller coaster car starts from the top of a hill which is 5 M higher t...In the given figure a ball of mass m is connected to an elastic spring of force constant K = mg/L through an inextensibl...A block of mass m = 0.1 kg is connected to a spring of unknown spring constant k. It is compressed to adistance x from r...system is placed on a rough horizontal surface having coefficient of frictional μ. The spring initial elongation an...If and displacement , then the work done is :-...