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
solong [7]
3 years ago
9

A 650-kg elevator starts from rest. It moves upward for 3.00 s with constant acceleration until it reaches its cruis- ing speed

of 1.75 m/s. (a) What is the average power of the elevator motor during this period
Physics
2 answers:
Nataly_w [17]3 years ago
7 0

Answer: P=5573.43\ W

Explanation:

Given

Mass of the elevator is M=650\ kg\\\

Time period of ascension t=3\ s

cruising speed v=1.75\ m/s

Distance moved by elevator during this time

Suppose Elevator starts from rest

\Rightarrow v=u+at\\\Rightarrow 1.75=0+a(3)\\\Rightarrow a=0.583\ s

Distance moved

\Rightarrow h=ut+0.5at^2\\\Rightarrow h=0+0.5\times 0.5833\times (3)^2\\\Rightarrow h=2.62\ m

Gain in Potential Energy is

\Rightarrow E=mgh\\\Rightarrow E=650\times 9.8\times 2.62\\\Rightarrow E=16,720.3\ N

Average power during this period is

\Rightarrow P=\dfrac{E}{t}\\\\\Rightarrow P=\dfrac{16,720.3}{3}\\\\\Rightarrow P=5573.43\ W

skelet666 [1.2K]3 years ago
5 0

Answer:

The power is 331.7 W.

Explanation:

mass, m = 650 kg

time, t= 3 s

initial  velocity,  u = 0 m/s

final velocity, v = 1.75 m/s

(a) The power is defined as the rate of doing work.

Work is given by the change in kinetic energy.

W = 0.5 m (V^2 - u^2)

W = 0.5 x 650 x 1.75 x 1.75 =  995.3 J

The power is given by

P = W/t = 995.3/3 = 331.7 W

You might be interested in
A particle is moving with velocity v(t) = t2 _ 9t + 18 with distance, s measured in meters, left or right of zero, and t measure
Alex787 [66]
V = t^2 - 9t + 18

position, s
s = t^3 /3 - 4.5t^2 +18t + C

       t = 0, s = 1 => 1=C => s = t^3/3 -4.5t^2 + 18t + 1

Average velocity: distance / time

   distance: t = 8 => s = 8^3 / 3 - 4.5 (8)^2 + 18(8) + 1 = 27.67 m
   Average velocity = 27.67 / 8 = 3.46 m/s

t = 5 s

     v = t^2 - 9t + 18 = 5^2 - 9(5) + 18 = -2 m/s
     speed = |-2| m/s = 2 m/s
 
Moving right
     V > 0 => t^2 - 9t + 18 > 0
     (t - 6)(t - 3) > 0

     => t > 6 and t > 3 => t > 6 s => Interval (6,8)

    => t < 6 and t <3 => t <3 s => interval (0,3)

    

Going faster and slowing dowm

acceleration, a = v' = 2t - 9
     a > 0 => 2t - 9 > 0 => 2t > 9 => t > 4.5 s
     Then, going faster in the interval (4.5 , 8) and slowing down in (0, 4.5)
     


4 0
3 years ago
How much force is required to accelerate a 2 kg mass at 3 m/s2
swat32

Force = (mass) x (acceleration)                  Newton's second law of motion.

Force = (2 kg) x (3 m/s²)  =  6 newtons.

3 0
3 years ago
A cook preparing a meal for a group of people is an example of
Fudgin [204]
Kinetic and potential energy he has the ability to make a meal and because he is making the meal

6 0
3 years ago
Joe has a mass of 40 kg, and Sally has a mass of 25 kg. They sit in class with a separation of 6 meters. Find the gravitational
goldfiish [28.3K]

Answer:

hmmmmmmmm

Explanation:

mmmmmmmmmmmmmmmmmmmmmmm  pay attention in class kid

4 0
3 years ago
Whiteout friction you could not, write, drive or fly and airplane. Why not?
aleksklad [387]

friction is the resistance that one surface or object encounters when moving over another. Due to gravity pulling everything down things need to friction in order to move

i hope this helps :/


7 0
3 years ago
Other questions:
  • An AC power source has an rms voltage of 120 V and operates at a frequency of 60.0 Hz. If a purely inductive circuit is made fro
    5·1 answer
  • You stand on a frictional platform that is rotating at 1.8 rev/s. Your arms are outstretched, and you hold a heavy weight in eac
    11·1 answer
  • The process in which acids and bases react so that the properties of both are lost to form water and a salt is called __________
    6·1 answer
  • Research suggests that depriving people of _____ sleep can cause emotional overreactions to threatening situations. A. NREM 1 B.
    9·1 answer
  • A plane electromagnetic wave with wavelength 3.0 m, travels in free space in the+xdirection with its electric field vector~E, of
    12·1 answer
  • The scientific method is
    9·2 answers
  • On his honeymoon, James Joule attempted to explore the relationships between various forms of energy by measuring the rise of te
    12·1 answer
  • Which type of electromagnetic waves has highest frequency​
    5·2 answers
  • The velocity of a passenger relative to a boat is -vpb. The velocity of the boat relative to the river it is moving on is vbr. T
    7·1 answer
  • Only Noice Produce Noice Pollution. Do You Agree? Give Reasons
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!