Determining Work Done by a Person on a Luggage

AI Thread Summary
To determine the work done by a person pulling luggage up a ramp, the work-energy theorem is suggested as a straightforward approach. The initial formula Wp = mgh is appropriate for calculating work done against gravity, but confusion arises with the inclusion of kinetic friction and applied force. It is clarified that the work done should not involve subtracting friction from the applied force, as the work is calculated based solely on the force exerted by the person over the distance moved. The discussion emphasizes the need to correctly apply the principles of physics to avoid miscalculations. Understanding the correct application of these formulas is crucial for accurately assessing the work done in both scenarios.
SerenaMay
Messages
1
Reaction score
0
Member advised to use the formatting template for all homework help requests
I'm trying to determine the work done by a person as they pull a luggage up a ramp. The ramp has a height of 5 m and the distance the person walks up is 20 m. The weight of the bag is also 10 kg.

I am trying to compare the work done by pulling the luggage up a ramp to carrying an equally heavy backpack up a ramp on one's back. The formula I found and used to find the Work the person did when carrying the backpack was Wp = mgh (Alternatively, Fn(d*cos(theta)) = Fh*h = mgh ?).

I was wondering if the formula for the pulling would be the same and/or how would the kinetic friction and possibly applied force on the luggage trolley handle be added in the equation. Or if I am wrong in both the formulas, what would be a more correct way of doing it?

From what I am thinking of, Wp = mgh*(applied force - kinetic friction) since the kinetic friction is holding the luggage back a bit but it is still significantly less than the applied force of the person pulling on the handle.
 
Physics news on Phys.org
Hi SerenaMay and welcome to PF.

The most straightforward approach to this problem is the work-energy theorem. Have you studied it?
 
SerenaMay said:
Wp = mgh*(applied force - kinetic friction)
That equation cannot be right. You already have mg as a force, and you are multiplying by another force.
Also, we want the work done by the person. Why would you subtract the frictional force?

The person applies a force. How do you normally find the work done by a given force?
 
Thread 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
Back
Top