Velocity of spring being made to go in a circle

AI Thread Summary
A 5 kg block attached to a spring with a relaxed length of 0.5 m and a spring constant of 250 N/m is made to move in a circle with a radius of 0.75 m. The spring stretches, and the net force can be calculated using F = k|s|, where the spring force is found to be 62.5 N. To find the speed of the block, the centripetal force formula F = (mv^2)/r should be used. The correct calculations lead to a speed of 3.1 m/s, confirming the answer provided in the practice exam. Understanding the distinction between linear and circular motion is crucial for solving this problem.
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Homework Statement


A 5 kg block is attached to the end of a spring with relaxed length 0.5 m and spring constant 250 N/m. The free end of the spring is held stationary and the block is made to go in a circle of radius 0.75 m, thus stretching the spring. What is the speed of the block (neglecting gravity and air resistance)?


Homework Equations


Fspring=k|s|
F*\Deltat= m*v
p=Fnet*\Deltat


The Attempt at a Solution


F=k|s|
F=250 (.5-.75)
F=-1000
F=mv?

I don't know what to do from here... this is on a practice exam, so I have the answer: 3.1 m/s, but I have no idea how to get to it. I tried F=mv, but got v to be 2.0, which isn't even an option. Please help!
 
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From
F=k|s|
You should get 62.5N with this, check your calculation.

Note that This is not linear motion.
You should be using the Centripetal force of Circular motion to find the answer,
in which F=(mv^2)/r.
 
Oops! I did a hasty calculation in my head... thanks for catching that! It makes perfect sense, too- thank you very much.
 

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