Question

You attach a block to the bottom end of a spring hanging vertically. You slowly let the block move down and find that it hangs at rest with the spring stretched by 18.0 cm. Next, you lift the block back up and release it from rest with the spring unstretched. What maximum distance does it move down

Answer 1

Answer:36 cm

Explanation:

Given

At Equilibrium extension a is 18 cm

suppose m is the mass of block

thus

$ka=mg$

$k=\frac{mg}{a}$

$k=\frac{mg}{0.18}$

Now if the block is released from un-stretched position

conserving Energy and supposing block moves x units down

$\frac{1}{2}kx^2=mgx$

$x=\frac{2mg}{k}$

$x=2mg\times \frac{0.18}{mg}$

$x=0.36 \approx 36 cm$