Finding the angle of an inclined plane

In summary, the problem involves a sled sliding down a slope at an angle θ with a kinetic coefficient of friction of μk = 0.050. The question is to determine the angle θ if the sled is observed to be traveling at a constant velocity, using the equation ∑F= ma. The correct answer is 2.7°, which may seem small due to the assumption that the sled was given a nudge to start sliding.
  • #1
Mitza
5
0
So here's the problem:

A sled slides down a long snow-covered slope that is at an angle θ to the horizontal. Kinetic friction acts on the sled as it slides where the kinetic coefficient of friction between the sled and snow is μk = 0.050. Ignore air-resistance when solving this problem.

If we observe the sled to be traveling at a constant velocity, what is θ? (in degrees)

So far I've drawn a force diagram and done this;
∑F= ma
∑F= 0
mgsinθ - μmgcosθ = 0
mgsinθ = μcosθ
tanθ = μ
arctanμ = θ

I know I've done something wrong because with that working the final angle is 2.9° which seems far too small.

Thanks in advance for any help!
 
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  • #2
Mitza said:
So here's the problem:

A sled slides down a long snow-covered slope that is at an angle θ to the horizontal. Kinetic friction acts on the sled as it slides where the kinetic coefficient of friction between the sled and snow is μk = 0.050. Ignore air-resistance when solving this problem.

If we observe the sled to be traveling at a constant velocity, what is θ? (in degrees)

So far I've drawn a force diagram and done this;
∑F= ma
∑F= 0
mgsinθ - μmgcosθ = 0
mgsinθ = μcosθ
tanθ = μ
arctanμ = θ

I know I've done something wrong because with that working the final angle is 2.7° which seems far too small.

Thanks in advance for any help!
Your answer is correct.
It probably seems too shallow because the static coefficient is a lot higher, more like 0.1-0.15. So you have to assume the sled was given a nudge to get it started.
 
  • #3
haruspex said:
Your answer is correct.
It probably seems too shallow because the static coefficient is a lot higher, more like 0.1-0.15. So you have to assume the sled was given a nudge to get it started.
Okay thank you for your response!
 

FAQ: Finding the angle of an inclined plane

What is an inclined plane?

An inclined plane is a simple machine that is a flat surface that is tilted at an angle. It is used to make it easier to move objects from one point to another by reducing the amount of force needed to lift or move the object.

How do you find the angle of an inclined plane?

The angle of an inclined plane can be found using the trigonometric ratio, also known as the tangent function. The formula is: angle = arctan (height/length). This means that the angle is equal to the inverse tangent of the ratio of the height of the inclined plane to its length.

Why is it important to know the angle of an inclined plane?

The angle of an inclined plane is important because it affects the amount of effort needed to lift or move an object. A smaller angle means that less force is needed to move the object, while a larger angle requires more force. It also affects the distance the object will travel when moved along the inclined plane.

What are the practical applications of finding the angle of an inclined plane?

The angle of an inclined plane is used in various real-life situations, such as calculating the angle of a ramp for wheelchair accessibility, determining the optimal angle for a roof to collect rainwater, and finding the most efficient angle for a skateboard ramp. It is also important in fields like engineering, construction, and physics.

Can the angle of an inclined plane be greater than 90 degrees?

No, the angle of an inclined plane cannot be greater than 90 degrees. This is because at 90 degrees, the inclined plane becomes a vertical wall and is no longer a flat surface. The angle can be less than 90 degrees, and in this case, it is called a positive angle. If the angle is greater than 90 degrees, it is considered a negative angle and is not a true inclined plane.

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