A block of mass m = 4.5 kg rests on a frictionless floor. It is attached to a spring with a relaxed length L = 3 m. The spring has spring constant k = 16 N/m and is relaxed when hanging in the vertical position. The block is pulled d = 3 m to one side. In this problem, the block is always constrained to move on the floor (i.e. it never leaves the floor).(adsbygoogle = window.adsbygoogle || []).push({});

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a) By what amount is the spring extended?

DL = m *

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b) What is the potential energy stored in the spring?

Uspring = J *

12.3 OK

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c) The block is released but is constrained to move horizontally on the frictionless floor. What is the maximum speed it attains?

|v|max= m/s *

2.34 OK

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Let's change the problem a bit. When the spring is vertical (hence, unstretched), the block is given an initial speed equal to 1.8 times the speed found in part (c).

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d) How far from the initial point does the block go along the floor before stopping?

Dmax = m *

4.287 OK

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e) What is the magnitude of the acceleration of the block at this point (when the spring is stretched farthest)?

|a| = m/s2

0.638 NO

HELP: What is the force exerted by the spring on the block when the spring is fully stretched?

I am not able to figure out part e. I'm stuck

here is what I did F = ma = k * delta L

Plugged in m , k and delta L

found a to be 8.25 m/s2, which is wrong, anybody tell me what is wrong?

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# Homework Help: Mass on Spring

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