How Much Power is Needed to Move an Elevator at 4.50 m/s?

[GalacticSnipes]

Homework Statement

An elevator cab has a mass of 4600 kg and can carry a maximum load of 1800 kg. If the cab is moving upward at full load at 4.50 m/s, what power is required of the force moving the cab to maintain that speed?

Homework Equations

P = W/T
W = F*D
F = M*A

The Attempt at a Solution

P = W/T
P = (F*D)/T
P = ((M*A)*D)/T
P = ((6400*9.8)*D)/T
I don't know what I should enter for D and T
Help, please?

 

[PhanthomJay]

D/T is equal to what ? (using kinematic equations ).

 

[GalacticSnipes]

Distance and Time

 

[PhanthomJay]

Distance divided by time equals _____? (Fill in the blank)

 

[GalacticSnipes]

oh velocity

 

[GalacticSnipes]

so the answer would be 6400*9.8*4.5 = 282240 Watts?

 

[PhanthomJay]

oh velocity

Well, D/T is average or constant speed , which is given.

 

[GalacticSnipes]

constant

 

[PhanthomJay]

so the answer would be 6400*9.8*4.5 = 282240 Watts?

so the answer would be 6400*9.8*4.5 = 282240 Watts?

Yes. You should round it off to say 280 kW.

 

[GalacticSnipes]

But 282.240 kW is the non rounded answer?

 

[PhanthomJay]

But 282.240 kW is the non rounded answer?

Yes.

 

[GalacticSnipes]

ok, thx