# A cord is used to vertically lower an initially stationary block of mass M at a constant downward acceleration of g/4. When the block has fallen a distance d, find a) The work done by cord's force on the block, b) the work done by gravitational force on the block, c) the kinetic enery of the block and d) the speed of the block. A 0.269 kg block of cheese lies on the floor of a 650 kg elevator cab that is being pulled upward by a cable through distance d1= 2.40 m and then through distance d2 = 10.5 m a)Through d, if the normal force on the block from the floor has constant magnitude Fn = 5.00 N, how much work is done on the cab by the force from the cable? b)Through d2, if the work done on the cab by the constant force from the cable is 98.60 kJ, what is the magnitude of Fn

SAGAR SINGH - IIT DELHI
879 Points
12 years ago

Dear student,

The correct option is b) in both the cases...

Apply newton's laws of motion to verify the result.

All the best.

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