How Do You Calculate the X-Component of Force from Potential Energy?

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To calculate the x-component of force from potential energy, the formula -dU/dx is used, where U is potential energy. Users are experiencing difficulties obtaining correct force values at specific positions, particularly at x = 5 cm and x = 25 cm. It is noted that the slope of the U-r graph, which represents the force, remains consistent between 20 cm and 40 cm. Participants suggest applying the same calculation method used at x = 5 cm to find the force at x = 25 cm. Accurate interpretation of the graph and careful attention to units are crucial for correct calculations.
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A particle has the potential energy shown in the figure. See link below. What is the x-component of the force on the particle at x =5, 15, 25, and 35 cm?

All answers are in N

http://img111.imageshack.us/img111/4988/figure2vn4.jpg

i know i should be using -dU/dx
but i keep getting the wrong answers when x = 5 cm
I get F = 1N
 
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Did you take into account the fact that the x-axis is marked in cm?
 
oh, thank you :-p
 
I'm actually having trouble when x = 25 cm. Is there any advice on how to figure it out?
 
sracks said:
I'm actually having trouble when x = 25 cm. Is there any advice on how to figure it out?

-dU/dx means the slope of U-r graph
slope of U-r graph between 20cm-40cm are the same.
 
sracks said:
I'm actually having trouble when x = 25 cm. Is there any advice on how to figure it out?
Use the same method used at x = 5 cm.
 

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