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Energy question, involving work, there is a missing variable?

  • #1

Homework Statement



A 613.0 kg mass is placed on a forklift that can generate 950 W of power. What is the constant speed of the forlift while lifting this load?

Homework Equations



W = F * change in Displacement ( or (F)(change in displacement)(costheta))

W = mg * Change in displacement

P = W/t
Ekinetic = 1/2mv^2

Work is in joules, power is in Watts.

The Attempt at a Solution



950 W = W/t (I don't have time or displacement)

W = mg * change in displacement
W = (9.5*613 )* change in displacement(which I do not have)
W = 6007.4 N *change in displacement
change in displacement = vAverage * change in time
change in time = all include velocity, which I am looking for.
?

Ekinetic = 1/2mv^2
xJ = (613.0kg/2)v^2
xJ = 306.5v^2
?


I feel like I need displacement or time, but I'm given neither. :\
 

Answers and Replies

  • #2
cepheid
Staff Emeritus
Science Advisor
Gold Member
5,192
35
W = F * change in Displacement
Good! Now what happens if you take both sides of this equation, and divide them by t?
 
  • #3

Homework Statement



A 613.0 kg mass is placed on a forklift that can generate 950 W of power. What is the constant speed of the forlift while lifting this load?

Homework Equations



W = F * change in Displacement ( or (F)(change in displacement)(costheta))

W = mg * Change in displacement

P = W/t
Ekinetic = 1/2mv^2

Work is in joules, power is in Watts.

The Attempt at a Solution



950 W = W/t (I don't have time or displacement)

W = mg * change in displacement
W = (9.5*613 )* change in displacement(which I do not have)
W = 6007.4 N *change in displacement
change in displacement = vAverage * change in time
change in time = all include velocity, which I am looking for.
?

Ekinetic = 1/2mv^2
xJ = (613.0kg/2)v^2
xJ = 306.5v^2
?


I feel like I need displacement or time, but I'm given neither. :\
take eqation w=mg*d
divide both side by t,then u will get p=mg*v
put the values of p,m&g,so find the velocity of forlift......
 
  • #4
Good! Now what happens if you take both sides of this equation, and divide them by t?
Ah...
take eqation w=mg*d
divide both side by t,then u will get p=mg*v
put the values of p,m&g,so find the velocity of forlift......

That is so ingenius, I love it! Thank you guys very much! :]
 

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