Block held against a spring going up a frictionless plane

AI Thread Summary
A 3 kg block is compressed against a spring (k=580 N/m) on a frictionless 25-degree incline and released from a compression of 0.18 m. The potential energy stored in the spring is calculated to be approximately 9.396 J. Participants discuss the need to find the height (h) the block reaches after release, noting that the initial and final speeds are zero. The correct approach involves equating the spring's potential energy to gravitational potential energy to find h, and then using the incline angle to determine the distance traveled along the incline. The discussion emphasizes that calculating speed is unnecessary for solving the problem.
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Homework Statement


A 3 kg block is held against a spring (k=580nt/m) at the bottom of a frictionless 25 degree incline. The spring is compressed 0.18m. How far along the incline does the block go when released.

Homework Equations


Usp=1/2kx^2

The Attempt at a Solution


So far the only thing I've been able to do was calculate the velocity which i got to be 1.65m/s if I did it correctly.

Usp= 1/2 * 580 * .18^2
= 9.396

then I did this equation but I didn't know exactly what h was that I was trying to calculate. I think i just ended up calculating how much the spring was compressed and I already knew that.

9.396 + (1/2)(3)(0) = (3)(9.8)(h) + (1/2)(3)(1.654^2)
9.396 = 29.4h + 4.103
h = .18
 
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did I not supply enough information?
 
Welcome to PF.

The PE at the bottom should really give you your height shouldn't it?
 
TaxiDriver113 said:

Homework Statement


A 3 kg block is held against a spring (k=580nt/m) at the bottom of a frictionless 25 degree incline. The spring is compressed 0.18m. How far along the incline does the block go when released.


Homework Equations


Usp=1/2kx^2



The Attempt at a Solution


So far the only thing I've been able to do was calculate the velocity which i got to be 1.65m/s if I did it correctly.

The speed at what position?

Actually, you don't need to find any speed to solve the problem. At the beginning and at the end of the motion (at the max height) the speed is zero.
Usp= 1/2 * 580 * .18^2
= 9.396

then I did this equation but I didn't know exactly what h was that I was trying to calculate. I think i just ended up calculating how much the spring was compressed and I already knew that.

9.396 + (1/2)(3)(0) = (3)(9.8)(h) + (1/2)(3)(1.654^2)
9.396 = 29.4h + 4.103
h = .18

You could simply do

9.396 J = 3 * 9.8 * h

find h and then use the angle to find the distance along the incline.
 
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