Physics problem, basketball dunk (Hookes law)

In summary: NIn summary, the problem is asking for the extent of bend in a basketball rim when a 95kg player hangs onto it after slam dunking a basketball 2m in the air. Using the equations Ep = 0.5 k x^2, Eg = mgh, and Ek = 0.5 m v^2, we can determine that the extent of the bend will be 0.15m.
  • #1
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Homework Statement


A 95kg basketball player slam dunks a basketball and hangs onto the rim. Find out how much the rim bends if its spring constant = 7400 N/m and the basketball rim is 2 m in the air.

Homework Equations


Ep = 0.5 k x^2
Ek = 0.5 m v^2
Eg = mgh

The Attempt at a Solution


The book got 0.15 m. My answer is way off, what did I do wrong? I think this should be right.

Ep1 + Ek1 + Eg1 = Ep2 + Ek2 + Eg2
Ep1 = 0, Ek1 = 0, Ek2 = 0

Eg1 = Ep2 + Eg2
mgh = (1/2)kx^2 + mg(2m - x)

1862 J = 3700x^2 N/m + 1862 J - 931x N

3700x^2 N/m - 931x N = 0

931x N( 3.97x / m - 1 ) = 0

x = 0 or 3.97x/m = 1

x = 1/(3.97/m) = 0.25 m.

Book got 0.15. My answer is way off and I'm not sure why it could be look this. Is my logic correct? Am I correct?
 
Last edited:
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  • #2
It is not entirely clear, but I don't think it is asking the maximum extent of the bend under SHM. It's a statics question: if the player hangs on for an arbitrarily long time, what will the extent of the bend settle out at?
 
  • #3
You are not given any speeds so there is no point in looking at kinetic energy. The problem is just "if a 95 kg object is hung from a spring with spring constant 7400 N/m, how far will the spring extend?"

95g=
 

1. What is Hookes law?

Hookes law is a principle in physics that states the force needed to extend or compress a spring by some distance is proportional to that distance. This means that if you double the force applied, the distance will also double.

2. How does Hookes law apply to a basketball dunk?

In a basketball dunk, Hookes law can be used to explain how the basketball bends and compresses when it is pushed down by the player's hand. The amount of force applied by the hand is proportional to the distance the basketball is pushed down.

3. What factors affect the application of Hookes law in a basketball dunk?

The factors that affect the application of Hookes law in a basketball dunk include the weight of the ball, the force applied by the player's hand, and the elasticity of the basketball. The weight of the ball and the force applied will determine the distance the basketball will compress, while the elasticity of the ball will determine how quickly it returns to its original shape.

4. Can Hookes law be used to calculate the height of a basketball dunk?

Yes, Hookes law can be used to calculate the height of a basketball dunk. By measuring the amount of force applied and the distance the basketball is compressed, the height of the dunk can be determined using the formula h = F/k, where h is the height, F is the force, and k is the spring constant.

5. Are there any limitations to using Hookes law in a basketball dunk?

Yes, there are some limitations to using Hookes law in a basketball dunk. The law assumes that the basketball is a perfect spring with a constant spring constant, which may not always be the case. Factors such as air resistance and the angle at which the ball is pushed down can also affect the accuracy of the calculations.

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