1. Jan 14, 2008

### pc21

1. A block of mass 12.0 kg slides from rest down a frictionless 32.0° incline and is stopped by a strong spring with k = 1.00 104 N/m. The block slides 3.00 m from the point of release to the point where it comes to rest against the spring. When the block comes to rest, how far has the spring been compressed?

2. K=F/x - K= spring constant

3. I really have no idea how to do this

2. Jan 14, 2008

Do you know conservation of energy?

3. Jan 14, 2008

### pc21

sort of PE=KE? is that what i need to use since there is no friction?

4. Jan 14, 2008

well, we have the initial Potential energy
Then, at the point of impact, we have less potential, because now some of that is kinetic.
Then, there is spring potential which counteracts all of the previous potential/kinetic energy.
So, express that algebraically.

5. Jan 14, 2008

### pc21

so do i have to subtract potential energy from the final kinetic energy?

6. Jan 14, 2008

### pc21

i just got it.
PE=mgh=KE=1/2mv2
then i plugged my numbers in and got x to be .19 and it was right
thanks

Last edited: Jan 14, 2008
7. Jan 14, 2008