(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A block of mass 12.0kg slides from rest down a frictionless 35degree

incline and is stopped by a strong spring with a force constant of

3.00 x 10^4 N/m. The block slides 3.00m from the point of release

to the point where it comes to rest against the spring. When the block

comes to rest, how far has the spring been compressed?

2. Relevant equations

W=deltaK

Vf^2 = vi^2 + 2a(deltay)

Wg + Ws = delta K

-mg + 1/2kx^2 = 1/2m(vi^2)

3. The attempt at a solution

I drew my picture and forces and then

I solved for the velocity at the moment it makes contact at the spring

Vf = sqrt(Vi^2 + 2(9.8m/s^2)(sin35)(3.0m) = 5.81m/s

Then I used -mg + 1/2kx^2 = 1/2m(vi^2)

I rearranged to be

x = sqrt 2(1/2mv^2 + mg)/K

x = sqrt 2(1/2)(12kg)(5.81)^2 + (12kg)(9.8m/s^2)(sin35) / 3.00 x 10^4 N/m

x = 540/30000

x = .018m

The book says .116m

I must not be on the right track. Any help would be appreciated.

Kevin

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

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# Homework Help: Spring Compression and block of mass

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