1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
max2010maxim [7]
3 years ago
6

A(n) 712 kg elevator starts from rest. It moves upward for 3.13 s with a constant acceleration until it reaches its cruising spe

ed of 1.93 m/s. The acceleration of gravity is 9.8 m/s 2 . Find the average power delivered by the elevator motor during this period. Answer in units of kW.
Physics
1 answer:
Monica [59]3 years ago
5 0

Answer:

P = 7.61kW

Explanation:

In order to calculate the power delivered by the elevator motor, you take into account the work done by the elevator against the gravitational force.

The work done by the elevator is given by:

W_g=(F-Mg)h=Mah     (1)

F: force of the motor

M: mass of the elevator = 712 kg

g: gravitational force = 9.8 m/s^2

h: vertical distance traveled by the elevator

a: acceleration of the elevator

You calculate the acceleration a by using the following formula:

a=\frac{v}{t}=\frac{1.93m/s}{3.13s}=0.616\frac{m}{s^2}       (2)

With this values you can calculate F from (1)

F-Mg=Ma\\\\F=Ma+Mg=(712kg)(0.616+9.8)m/s^2=7416.19N     (3)

Furthermore, you have that the work is equal to the change in the kinetic energy:

Mah=\frac{1}{2}M(v^2-v_o^2)     (2)

v: final speed of the elevator = 1.93 m/s

vo: initial velocity = 0 m/s

From the equation (2) you can calculate the vertical distance h:

h=\frac{v^2}{2a}=\frac{(1.93m/s)^2}{2(0.616m/s^2)}=3.02m

Then, the work done by the elevator is

W_e=Fh=(7416.19N)(3.02m)=22422.53J

The quotient of the work We and time (3.13 s) is the power delivered by the motor:

P_e=\frac{W_e}{t}=\frac{22422.53J}{3.13s}=7613.74W\approx7.61kW

The power delivered by the elevator is 7.61kW

You might be interested in
Alexis is studying how lenses work. She looks through a
Kryger [21]
It would be the 3rd one
6 0
3 years ago
A proton moving at 8.00 106 m/s through a magnetic field of magnitude 1.72 T experiences a magnetic force of magnitude 7.20 10-1
gladu [14]

Answer:

19.1 deg

Explanation:

v = speed of the proton = 8 x 10⁶ m/s

B = magnitude of the magnetic field = 1.72 T

q = magnitude of charge on the proton = 1.6 x 10⁻¹⁹ C

F = magnitude of magnetic force on the proton = 7.20 x 10⁻¹³ N

θ = Angle between proton's velocity and magnetic field

magnitude of magnetic force on the proton is given as

F = q v B Sinθ

7.20 x 10⁻¹³ = (1.6 x 10⁻¹⁹) (8 x 10⁶) (1.72) Sinθ

Sinθ = 0.327

θ = 19.1 deg

4 0
3 years ago
if grapefruit juice has a ph of 3.0 and egg white have a ph of 8.0, which contains more h+ ions ? how many more ?
hammer [34]
Grapefruit juice. The more acidic something is the more h it has. 
6 0
3 years ago
Read 2 more answers
A pan of ice is placed over a flame.
AveGali [126]
A. The molecules start packed together very tightly in a solid. Then when it turns to water, the molecules can move around each other freely, but still contained. When water turns to vapor, the molecules are going crazy moving around. They are not contained at all and bounce of of each other freely.

b. The temperature rises. (ice turns to water at 33 degrees and water turns to vapor at 212 degrees)
8 0
3 years ago
Question: Which one of the following foods contains simple carbohydrates?
Katena32 [7]

Answer:

Milk

Hope this helps,if not sorry

5 0
3 years ago
Other questions:
  • Which of these characteristics did all of the five waves of immigrants have in common A. They all had the same political beliefs
    6·1 answer
  • Suppose a treadmill has an average acceleration of 4.7x10^-3 m/s. a)how much does its speed change after 5min? b)if the treadmil
    9·1 answer
  • The current in a hair dryer measures 22 amps. The resistance of the hair dryer is 14 ohms what is the voltage
    12·1 answer
  • How much force is required to accelerate a 2kg mass at 3 m/s2? answer key?
    10·1 answer
  • Why electrons carry a net energy but not a net a current in case of thermal conduction
    10·1 answer
  • 100 POINTS. PLEASE PROVIDE EXPLANATION
    5·1 answer
  • A 2.00 kg mass is located at (4.00 m, 0.00 m, 0.00 m) and a 4.00 kg mass is located at (0.00 m, 3.00 m, 0.00 m). If this system
    6·1 answer
  • Reflection off of a smooth surface like a mirror is an example of diffuse reflection.
    6·2 answers
  • a blackbody is radiating with a characteristic wavelength of 9 microns what is the blackbody temperature answer in kelvin
    12·1 answer
  • . A girl of mass 35 kg and boy of mass 25 kg are connected by a light rope. They move horizontally in a skating rink. A second r
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!