# Steel mass attached to the ceiling, maximum height gain if it is hit

1. Apr 28, 2013

### needingtoknow

1. The problem statement, all variables and given/known data
A 275 KG steel mass is held by a long cable to the ceiling. Daniel hits the steel mass horizontally and gives it a horizontal speed of 1.75 m/s. Assuming there is no friction, determine the maximum height gain, in centimetres, of the steel mass after the collision.

2. Relevant equations
W = Fd
E = 1/2mv^2
Eg = mgh

3. The attempt at a solution

These are the only three equations given in the question, and no angle is given in the question so how would I calculate the height at which the pendulum moves (if the question is suggesting that the steel block is moving in a pendulum fashion which I am not entirely sure of)

2. Apr 28, 2013

### Infrared

Try conservation of energy. When it is at its highest point, the mass is not moving so all of its initial kinetic energy has been converted into gravitational potential energy.

3. Apr 28, 2013

### needingtoknow

All right so using the law of conservation of energy here is what I got.
1/2mv^2 + mgh = 1/2mv^2 + mgh
1/2(275)(1.75) + 0 = 0 + (275)(9.8)h
240.625/2695 = h
h = 8.9 cm but the answer is 15.6 cm

4. Apr 28, 2013

### needingtoknow

Oh and I used the rest position of the steel block as my reference point because they didnt give the distance off of the ground.

5. Apr 28, 2013

### Infrared

Don't forget to square the velocity.

6. Apr 28, 2013

### needingtoknow

Oh never mind I got the answer. Thanks for the helps HS-Scientist!

7. Apr 28, 2013

### needingtoknow

Yeah just realized that! I got 15.6 cm after I fixed that.