Calculating Angle and Height in Conservation of Energy Problem with Friction

In summary, the skier slide down a slope at an angle of 12 degrees. The kinetic friction force was 41 N and the skier's initial speed was 0.65 m/s.
  • #1
TheMasterFool
2
0

Homework Statement


A 46 kg skier slides down a slope 21.7 m long, incilned at an angle θ to the horizontal. The magnitude of the kinetic friction force is 41 N. The skier s initial speed is 0.65 m/s and the speed at the bottom of the slope is 7.19 m/s. determine the angle θ from the law of conservation of enegery. Air resistance is neglible


Homework Equations



PE=mgy, KE= 1/2mv^2, W=F*d, Ff=μmgsinθ

The Attempt at a Solution


My attemp at the equation was based on the law of conservation of energy with this resulting formula

(mgh+1/2mv^2-mgh-1/2mv^2)/Ff*d=sinθ

I can't figure out how to find the height without an angle or vice versa, i ve been trying to figure it out for the last little bit with no success. I feel like I m missing just one step
 
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  • #2
TheMasterFool said:

Homework Statement


A 46 kg skier slides down a slope 21.7 m long, incilned at an angle θ to the horizontal. The magnitude of the kinetic friction force is 41 N. The skier s initial speed is 0.65 m/s and the speed at the bottom of the slope is 7.19 m/s. determine the angle θ from the law of conservation of enegery. Air resistance is neglible


Homework Equations



PE=mgy, KE= 1/2mv^2, W=F*d, Ff=μmgsinθ

The Attempt at a Solution


My attemp at the equation was based on the law of conservation of energy with this resulting formula

(mgh+1/2mv^2-mgh-1/2mv^2)/Ff*d=sinθ

I can't figure out how to find the height without an angle or vice versa, i ve been trying to figure it out for the last little bit with no success. I feel like I m missing just one step


How much work was done against friction during the slide?
 
  • #3
Hey I think i figured it out, I took sin theta outta my energy conservation since it gave me the resisting force of 41N. I then used the energy conservation formula to find height and then O/H sin -1 to find my angle which turned out to be sig fig 12 degrees. It feels right but I guess I ll find out and post again.
 

Related to Calculating Angle and Height in Conservation of Energy Problem with Friction

1. What is work?

Work is a scientific concept that refers to the transfer of energy from one object to another. It is the product of the force applied to an object and the displacement of that object in the direction of the force.

2. How is work related to friction?

Friction is a force that resists the motion of an object. When an object is moving against a surface, friction acts in the opposite direction of the motion, reducing the speed of the object. This means that work must be done to overcome the force of friction.

3. What factors affect the amount of work required to overcome friction?

The amount of work required to overcome friction depends on several factors, including the type of surface involved, the force applied, and the distance over which the force is applied. The roughness and texture of the surface can also affect the amount of work needed to overcome friction.

4. Can friction ever be beneficial in terms of work?

Yes, friction can be beneficial in certain situations. For example, friction is necessary for walking or driving, as it allows our feet and tires to grip the ground and move forward. Additionally, friction can be used to slow or stop objects, which can be useful for safety purposes.

5. How is friction related to energy conservation?

Friction plays a role in energy conservation because it can convert kinetic energy (the energy of motion) into thermal energy (heat). This means that some of the energy used to overcome friction is lost in the form of heat, which cannot be used for work. Therefore, reducing friction can help conserve energy in certain situations.

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