Initially sliding with a speed of 2.5 m/s, a 2.0 kg block collides with a spring and compresses it 0.35 m before coming to rest. What is the force constant of the spring?

2 answers

K= N/M
Two equations:

KE=1/2mv^2

and

PE=1/2kx^2

Where:

PE=potential energy
KE=Kinetic energy
m=mass of the block
v=velocity of the block
k=spring constant
and
x=0m-0.35m=-0.35m

Set both equations equal together and solve for k:

1/2mv^2=-1/2kx^2

k=mv^2/x^2

k=[2.0kg*(2.5m/s)^2]/(0.35m)^2

Answer should contain no more than two significant figures.