Help! Will award a medal and fan: A spring with k = 54 N/m hangs vertically next to a ruler. The end of the spring is next to the 21-cm mark on the ruler. If a 3.0-kg mass is now attached to the end of the spring, and the mass is allowed to fall, where will the end of the spring line up with the ruler marks when the mass is at its lowest position?

Question

mortonsalt · Answer

So you're given:
k= 54 n/m
x at the end mark is 21 cm 
mass of object = 3.0kg

Do you know what formula to use? :)

mortonsalt · Answer

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With this, would you then agree that a is caused by the force applied by the mass? In other words: the change in displacement is caused by the weight?