subject
Physics, 04.11.2020 16:40 sbailey0962

Please help with C) An elevator car has a mass of 1,540 kg and is carrying passengers having a combined mass of 220 kg. A constant friction force of 4,025 N retar ds its motion.

a. How much power must a motor deliver to lift the elevator car and its passengers at a constant speed of 2.30 m/s?

P = (1,760 kg)(9.80 m/s2) + (4,025 N)(2.30 m/s) = 48927 W

b. What power must the motor deliver at the instant the speed of the elevator is v if the motor is designed to provide the elevator car with an upward acceleration of 1.80 m/s2?

P = ((1,760 kg)(1.80 m/s2 + 9.80 m/s2) + 4,025 N)v = 24441 v

c. Suppose the same (1,540 kg) elevator with the same (220 kg) load descends at 2.30 m/s. What is the power delivered by the motor? Energy must be removed to slow the elevator's descent.

P = W

ansver
Answers: 2

Another question on Physics

question
Physics, 21.06.2019 20:30
When a book falls from a shelf to the ground without anyone pushing on it, no work is done on the book. true or false
Answers: 1
question
Physics, 22.06.2019 20:20
An electron is trapped at a defect in a crystal. the defect may be modeled as a one-dimensional, rigid-walled box of width 1.00 nm. (a) sketch the wavefunctions and probability densities for the n 1 and n 2 states. (b) for the n 1 state, nd the probability of nding the electron between x1 0.15 nm and x2 0.35 nm, where x 0 is the left side of the box. (c) repeat (b) for the n 2 state. (d) calculate the energies in electron volts of the n 1 and n 2 states
Answers: 1
question
Physics, 22.06.2019 21:00
What is the efficiency of an engine that does 80 j of work and exhausts 320 j of heat while taking in 400 j of heat ? a. 10% b. 20% c. 80% d. 25%
Answers: 1
question
Physics, 22.06.2019 21:10
Which of the following is a measure of the amount of light a star directly emits?               a.  luminosity    b.  intensity    c.  wavelength    d.  brightness
Answers: 2
You know the right answer?
Please help with C) An elevator car has a mass of 1,540 kg and is carrying passengers having a comb...
Questions
question
Mathematics, 27.02.2021 14:00
question
Mathematics, 27.02.2021 14:00
question
Biology, 27.02.2021 14:00
question
Mathematics, 27.02.2021 14:00
question
Arts, 27.02.2021 14:00
question
Mathematics, 27.02.2021 14:00
Questions on the website: 13722363