A grade 12 physics dynamics problem

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SUMMARY

The discussion focuses on solving a grade 12 physics dynamics problem involving an 80 N sled being pulled up a 15-degree hill with a 35 N force at a 35-degree angle to the horizontal. The objective is to determine the coefficient of kinetic friction between the sled and the snow, as well as the acceleration of a 50 kg boy who jumps on the sled and slides down the hill. Key equations include Fnet = ma and Ffk = μ * fn, which are essential for analyzing the forces acting on the sled and the boy.

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Knowledge of free body diagrams (FBD)
  • Familiarity with trigonometric functions in physics
  • Concept of kinetic friction and its calculation
NEXT STEPS
  • Study the application of free body diagrams in dynamics problems
  • Learn how to resolve forces using trigonometric functions
  • Explore the concept of kinetic friction and its role in motion
  • Practice solving problems involving inclined planes and forces
USEFUL FOR

This discussion is beneficial for high school physics students, educators teaching dynamics, and anyone looking to improve their problem-solving skills in mechanics involving forces and motion on inclined planes.

Scatteredheroes
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Homework Statement


A boy drags his 80 n sled at a constant speed up a 15 degree hill. He does so by pulling with a 35 n force on a rope attached to a sled. If the rope is inclined at 35 degrees to the horizontal, what is the coefficient of kinetic friction between snow and sled

At the top of hill, he jumps on sled (weighing 50 kg, the boy) and slides down the hill. What is his acceleration?

Homework Equations



Fnet= ma

Ffk = mew fn

And so on, so forth.

The Attempt at a Solution


[/B]

I drew a FBd, including angles, and force locations, but I do not know how to use the angles to find the required forces. As well, as a general question, how do you use angles in the diagram to find things?
 
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My main problem is that I know the Fg, which is ma (9.8)

After that, I get slightly lost due to the angles, and am unable to find even the most basic fn.
 
Scatteredheroes said:
I drew a FBd, including angles, and force locations, but I do not know how to use the angles to find the required forces.
if you can't post the diagram, at least try to describe it. What forces operate, what magnitudes and what directions?
Invent symbols for all values so that the algebra can be done symbolically. Only plug the numbers back in at the end.
 

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