# Need some help on this physics question

1. Oct 29, 2012

### bobo2210

If a ball of mass of 0.1kg is placed at the end of the compressed spring
(k=4000N/m). If the spring is compressed 1cm...
a. What will the kinetic energy of the ball be?
b. How fast is it moving?
c. What is its momentum?
d. What was the force on the ball from the spring?
e. If it took 0.01s to go from compression to ‘launch’, what is the impulse?
f. What was the power?
g. If this ball was on the bottom of a frictionless roller coaster track, what is
the maximum height that the loop could be?
h. What is the speed of the ball at the bottom of the loop?
i. If this 0.1kg mass collides with a 1.0kg mass that was at rest, what is the
momentum of the system after the collision? (this is an elastic collision)
j. What are the velocities (magnitude and direction) of 0.1kg and 1.0kg
masses

2. Oct 29, 2012

### Staff: Mentor

Its good to draw a picture of the setup and list the equations that you think will help solve the problem and you need to show some work before we can help.

3. Oct 29, 2012

### PeterO

Is this an ideal (massless) spring - where all the energy stored is to be imparted to the ball, or a real spring, where the energy stored is shared between the ball and pieces of the spring?
For that matter -especially considering part (d.) has the spring been released yet?

4. Oct 30, 2012

### bobo2210

What I got for (a)
is KE=1/2*mv^2
KE= 1/2*(0.1kg)*(0.01m/s)= 0.0005J
b) the ball is moving slow
then I didn't know how to find the momentum

5. Oct 30, 2012

### PeterO

What made you think it was travelling at 0.01 m/s when you did part (a)?