# Cell Phone Dropping

1. Jul 15, 2014

### gembi

1. The problem statement, all variables and given/known data
A hip kid is sitting down listening to music on his cell phone. The ear buds connected to the phone are inserted in his ears firmly and the phone is in his pocket. As the kid pulls something out of his pocket, the phone falls out and freely falls until just centimeters above the ground (irrelevant how far). The phone is stopped as the headphone cord becomes taught. The mass of the phone is 143 grams and the distance the phone dropped was 50 centimeters. The mass of the kid's head was 5 kilograms. Imagining that there is no resistance from the head and the ear buds stay in the ears, answer the following question:

2. Relevant equations
What was the a) force on the head and b) acceleration of the head?

3. The attempt at a solution
I have a possible answer and just want to check if I am right. Can someone tell me what they get? Thank you.

2. Jul 15, 2014

### Staff: Mentor

Hi gembi. Welcome to Physics Forums.

Do I have this right .... the head falls off?

3. Jul 15, 2014

### gembi

No, my professor said that the head just acts like it would in real life. When the phone stops it jerks the head downward a little bit. My professor wants to know the force and acceleration. caused by this

4. Jul 16, 2014

### CWatters

You should show your attempt when requesting help/confirmation.

5. Jul 16, 2014

:rofl::rofl: