# Homework Help: Help with oscillation problem thanks

1. Nov 6, 2011

### jlin94

help with oscillation problem!!! thanks

i have no idea how to do this. could someone please explain how to do this. thank you, really appreciate it

A mass of 311 g connected to a light spring
of force constant 37.2 N/m oscillates on a
horizontal, frictionless track. The amplitude
of the motion is 7.6 cm.

1. Calculate the total energy of the system.
Answer in units of J

2. What is the maximum speed of the mass?
Answer in units of m/s

3. What is the magnitude of the velocity of
the mass when the displacement is equal to
1.74 cm?
Answer in units of m/s

2. Nov 6, 2011

### grzz

Re: help with oscillation problem!!! thanks

When the spring is fully extended, the mass is at rest. Hence at this point in time there is no KE and the energy is fully due to the elastic PE of the spring.
Do you know the formula for the elastic PE of a spring?