Physics - Springs?

Question

A 6.60 kg mass hanging from a spring scale is slowly lowered onto a vertical spring.

1) What does the spring scale read just before the mass touches the lower spring?

2) The scale reads 22.0 N when the lower spring has been compressed by 1.70 cm. What is the value of the spring constant for the lower spring?

3) At what compression length will the scale read zero?


ANY and ALL help is greatly appreciated. Thanks!

Answer 1

This problem is poorly constructed. "slowly" does not tell what are the accelarations in all the cases. Now, since there is no data on accelaration at all, let us assume that all the accelarations are zero. The mass always move at a constant speed--it can not happen in reality, of course.

1) 6.60kg*9.81m/s^2 = 64.7N
2) Applying F = -kX, we have:
k = F/X = (64.7N - 22.0N)/(1.70cm) = 2.51 kN/m
3) Applying F = -kX, we have:
X = F/k = 64.7N/(2.51 N/m) = 2.58 cm