Question

What is the deflection of a spring?
As in this question
A ball of mass 2kg is dropped from a height if 20cm on a spring of stiffness k=1225 N/m. Find the maximum deflection of the spring.

Answer 1

Use the law of conservation of energy.
Potential energy of the object with mass m at the height h is equal to \[\ E=mgh\]
and the potential energy of a spring is equal to \[\ E_{spring}=\frac{1}{2}kx^2\]
where k - spring constant, x - displacement

Since all the gravitational potential energy will be transformed to the spring potential energy, its quite easy to figure out the displacement from this two equations :D.

Answer 2

Wow thats it! Awesome!
This gives x=8cm.
Thats the maximum deflection right?
Thanks a lot!

Answer 3

yes it is.