Question

In: Physics

A 1800kg elevator accelerates upward at 1.40m/s2 for 10.0m , starting from rest. How much work...

A 1800kg elevator accelerates upward at 1.40m/s2 for 10.0m , starting from rest.

How much work does gravity do on the elevator?

How much work does the tension in the elevator cable do on the elevator?

Use the work-kinetic energy theorem to find the kinetic energy of the elevator as it reaches 10.0m .

What is the speed of the elevator as it reaches 10.0m ?

Expert Solution

Here ,

work done by gravity = -mg * h

work done by gravity = -1800*9.8 * 10

work done by gravity = -176400 J

the work done by gravity is -176400 J

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tension in the cable is

T = 1800 *(9.8 + 1.40)

T = 20160 N

work done by tension = T*d

work done by tension = 20160 * 10

work done by tension = 201600 J

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Using work energy theorum

kinetic energy = 201600 - 176400

kinetic energy = 25200 J

the kinetic energy of the elevator is 25200 J
------------------------------------------------

now,

0.5 * m * V^2 = KE

0.5 * 1800 * v^2 = 25200

v =5.3 m/s

the speed of the elevator is 5.3 m/s

genius_generous answered 2 years ago

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