Trouble with Conservation of Energy And Friction

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SUMMARY

The discussion centers on the conservation of energy in the context of a hockey puck sliding on ice and coming to a stop due to friction. The initial energy (Ei) is calculated using the formula 0.5mv02, while the energy lost to heat (Eth) is expressed as μk∫ndx, simplifying to Eth=μknΔx when the normal force (n) is constant. The participant encounters confusion when equating Ei to Eth, leading to a discrepancy in mass (m) in their calculations. Ultimately, the participant realizes their mistake and acknowledges the error without seeking further clarification.

PREREQUISITES
  • Understanding of basic physics concepts such as energy conservation and friction
  • Familiarity with kinematic equations, particularly those involving velocity and acceleration
  • Knowledge of calculus, specifically integration for calculating work done by friction
  • Basic grasp of the relationship between mass, velocity, and energy
NEXT STEPS
  • Review the principles of conservation of energy in physics
  • Study the effects of friction on motion, focusing on the coefficient of friction (μk)
  • Learn how to apply kinematic equations to solve for distance and time in motion problems
  • Explore integration techniques for calculating work done in physics scenarios
USEFUL FOR

Students studying physics, educators teaching energy conservation principles, and anyone interested in understanding the dynamics of motion and friction in real-world applications.

MrBillyShears
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Ok, I'm driving myself mad, so if someone could settle this for me, that would be helpful. So, I'm imagining something like a hockey puck going across ice and coming to a stop. I'm trying to account for the initial energy, Ei, and the final energy, Ef. So this hockey puck starts with a velocity, v0, a mass, m, and of course under the influence of gravity, g. So, its Ei is.5mv02. Now, to account for the heat released, you use Eth=μk∫ndx, (n is the normal force). Now, since n is constant in this case, it reduces to Eth=μknΔx. Now we find Δx by finding the time it takes for the puck to come to rest, at+v0=0, -μkgt+v0=0, then we put that time in for the formula, .5at2+v0t=Δx. Then, we set Ei equal to Eth, but I get .5mv02=.5v02, so, what happened to the m? Why am I not getting equal things?
 
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Never mind, my mistake. Don't know how to delete it.
 

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