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

In summary, the problem involves finding the constant speed of a forklift with a 613.0 kg load, given that the forklift can generate 950 W of power. The equations used are W=mg*d, P=mg*v, and Ekinetic= 1/2mv^2. By taking both sides of the equation P=mg*v and dividing by t, the solution is found to be v=P/(mg).
  • #1
oddcitations
15
0

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. :\
 
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  • #2
oddcitations said:
W = F * change in Displacement

Good! Now what happens if you take both sides of this equation, and divide them by t?
 
  • #3
oddcitations said:

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 equation 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
cepheid said:
Good! Now what happens if you take both sides of this equation, and divide them by t?

Ah...
nikhil khatri said:
take equation 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! :]
 
  • #5


I can suggest the following approach to solve this problem:

1. Start by defining the variables given in the problem:
- Mass (m) = 613.0 kg
- Power (P) = 950 W

2. Identify the missing variable:
- The problem states that there is a missing variable, and based on the equations provided, it seems like the missing variable is either time (t) or displacement (x).

3. Use the equations provided to determine the missing variable:
- The equation W = F*d (work equals force times displacement) can be rearranged to solve for displacement: d = W/F. This means that if we can determine the work done (W) and the force (F), we can find the displacement (d).
- The equation P = W/t (power equals work divided by time) can also be rearranged to solve for time: t = W/P. This means that if we can determine the work done (W) and the power (P), we can find the time (t).
- The equation Ekinetic = 1/2mv^2 (kinetic energy equals one half times mass times velocity squared) can be rearranged to solve for velocity: v = √(2E/m). This means that if we can determine the kinetic energy (E) and the mass (m), we can find the velocity (v).

4. Look for additional information or assumptions:
- The problem does not provide any additional information or assumptions, so we will have to use the equations to find the missing variable.

5. Choose an appropriate equation and solve for the missing variable:
- Since we are looking for the constant speed of the forklift while lifting the load, we can use the equation for kinetic energy (Ekinetic = 1/2mv^2). We know the mass (m) and can calculate the kinetic energy (E) using the power (P) and time (t) given in the problem.
- Substituting the values into the equation, we get: E = 1/2 * 613.0 kg * v^2
- We also know that power (P) = 950 W, and time (t) is still unknown. Rearranging the equation for time, we get: t = W/P = (1/2 * 613.0 kg * v^2)/950 W
 

1. What is the formula for calculating work?

The formula for calculating work is W = F * d, where W represents work, F represents force, and d represents distance.

2. How is energy related to work?

Energy and work are closely related as work is the transfer of energy from one form to another. When work is done on an object, energy is transferred to that object, and when work is done by an object, energy is transferred away from that object.

3. What is the missing variable in the energy question involving work?

The missing variable in the energy question involving work can be either work, force, or distance. It depends on which two variables are given and which one is being asked to be solved for.

4. How do you calculate the force needed to do a certain amount of work?

To calculate the force needed to do a certain amount of work, divide the work by the distance. The resulting value will be the force needed to do that amount of work.

5. What are the units of measurement for work and energy?

Work and energy are both measured in joules (J) in the SI (International System of Units) system. In some other systems, they may also be measured in foot-pounds (ft-lb) or calories (cal).

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