Calculating Speed on a Snow Sled with Frictional Force

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SUMMARY

The discussion focuses on calculating the speed of a person on a snow sled with a total mass of 60.0 kg descending from a height of 24.0 m, while experiencing a constant frictional force of 70.0 N. The relevant equations include potential energy (PE = mgh), kinetic energy (KE = 1/2mv²), and work done against friction (W = Fd). The correct application of these equations leads to the conclusion that the sled's speed at the bottom of the hill is approximately 66.77 m/s, although there was confusion regarding the use of the spring constant equation.

PREREQUISITES
  • Understanding of potential energy and kinetic energy concepts
  • Knowledge of work and energy principles in physics
  • Familiarity with frictional forces and their impact on motion
  • Ability to perform dimensional analysis for physical equations
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  • Review the principles of energy conservation in mechanical systems
  • Study the effects of friction on motion and energy loss
  • Learn about dimensional analysis and its importance in physics
  • Explore advanced applications of work-energy principles in real-world scenarios
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This discussion is beneficial for physics students, educators, and anyone interested in understanding the dynamics of motion involving friction and energy conservation principles.

hatcheezy
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Homework Statement


A person on a snow sled(total mass of 60.0kg) starts from rest at a vertical height of 24.0m above the bottem of the hill. If aconstant frictional force of 70.0 N opposes their motion as they slide down the hill and the length of the slope is 65.0m, whta is their speedat the bottem of the hill?


Homework Equations


PE = KE + W
mgh = 1/2mv2 + 1/2kx2


The Attempt at a Solution


(60kg)(9.8m/s2)(24m) = 1/2(60kg)v2 + 1/2(70N)(65m)2

14112 = 30v2 +147875

v=66.77m/s ??
 
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1/2kx^2? That's the equation for a spring, not for the energy lost due to friction.

Just check your dimensional analysis, your units don't make sense.
 
Recall the equation for Work Done...
 

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