00:01
Hi, the given data can be analyzed as the mass of the elevator car m car is equal to 1500 kilograms, displacement of the car delta y is equal to 40 meters, frictional force f s is equal to 100 newton, acceleration due to gravity g is equal to 9 .8 meters per second square.
00:34
A non -conservative force work depend on the path the object takes between its ultimate position and initial position.
00:44
The work done on an object is determined by multiplying the force magnitude and projecting the displacement and force direction.
00:53
That is w is equal to f into d, where f is the force and d is the displacement.
01:02
Moving to the a part of the question, where we have to find the work done on elevator car by its cable.
01:16
The newton's second law says that sigma f y is equal to f cable minus m g minus f s is equal to m a y, where f is the force, m is the mass and g is the acceleration due to gravity and a is the acceleration.
01:38
Now, a y is equal to 0 since velocity is constant.
01:44
F cable is equal to m g plus f s.
01:50
We know that work done by some force is given by w is equal to f d cos theta.
01:59
So, the work done by the cable force on the car during the process is given by w cable is equal to f cable into delta y into cos 0.
02:16
That is equal to m g plus f s into delta y and on substituting the values 1500 into 9 .8 plus 100 into 40.
02:37
This the final answer is w cable is equal to 5 .92 into 10 to the power 5 joules.
02:52
Moving to the b part, where we have to determine the work done on the lift by gravitational force in this process.
03:03
Formula is w cable is equal to f g d cos theta...