A man of mass is standing in an elevator. If the elevator is moving up with an acceleration then what is the work one by normal reaction of the floor of the elevator on the man when elevator moves by a distance 12m?
Step 1: Given
Mass of the man:
Distance moved by lift:
Acceleration due to gravity is .
Acceleration of the lift: (negative because the lift is going upwards, moving against earth's gravity)
The resultant acceleration is .
Work done is .
Step 2: Formula used
Step 3: Find the resultant acceleration by subtracting the acceleration of lift from acceleration due to gravity.
Step 4: Find the force using the formula and substitute the value of g and m (Take only the magnitude of acceleration as the negative sign only indicate direction and have no affect on value).
Step 5: Find the work done using the formula
Hence, option (A) is correct.