A cable lifts a 1370 kg elevator at a constant velocity for a distance of 42 m. What is the work done by each of the following?
(a) the tension in the cable (J)
(b) the elevator's weight (J)
work by tension in cable if the car is not accelerating=mgh
workweight=-mgh
This assumes the elevator was moving initially, if it was stopped then one has to add the final KE the elevator has. THe problem is poorly written in that regard.
a) 411,600
b) -42000
I need help!
I do not Know :(
To find the work done by the tension in the cable, we can use the formula:
Work = force x distance
The force can be found using the equation:
Force = mass x acceleration
Since the elevator is moving at a constant velocity, there is no acceleration. Therefore, the force exerted by the tension in the cable is equal to the weight of the elevator, which can be calculated using:
Weight = mass x gravity
To find the work done by the elevator's weight, we can use the same formula:
Work = force x distance
Where the force is the weight of the elevator and the distance is the vertical distance moved.
Let's calculate the answers:
(a) Work done by the tension in the cable:
First, we calculate the force exerted by the tension in the cable:
Force = mass x acceleration
Since the elevator is moving at a constant velocity, the acceleration is zero. Thus, the force is:
Force = mass x acceleration
= (1370 kg) x (0 m/s^2)
= 0 N
Now, we can calculate the work done by the tension in the cable using the formula:
Work = force x distance
= (0 N) x (42 m)
= 0 J
Therefore, the work done by the tension in the cable is 0 Joules.
(b) Work done by the elevator's weight:
First, we calculate the weight of the elevator:
Weight = mass x gravity
= (1370 kg) x (9.8 m/s^2)
≈ 13426 N
Now, we can calculate the work done by the elevator's weight using the formula:
Work = force x distance
= (13426 N) x (42 m)
≈ 563892 J
Therefore, the work done by the elevator's weight is approximately 563892 Joules.