# Height of a drop in a dripping faucet

1. Nov 21, 2014

### krackers

• Poster informed about mandatory use of homework template.
This is from question 1 of the F=MA 2012 exam:

Consider a dripping faucet, where the faucet is 10 cm above the sink. The time between drops is such that when one drop hits the sink, one is in the air and another is about to drop. At what height above the sink will the drop in the air be right as a drop hits the sink?

First, I don't quite get the problem. What do they mean by "when one drop hits the sink, one is in the air and another is about to drop." Does this mean that it just exited the faucet when the other hits the sink? If so, isn't the answer to the question 10?

Regardless, I know that the time it takes for a drop to travel from the faucet to the sink is found from:

10 =980(t/2)^2

which gives that t=1/7, but I am not sure how to use that information.

2. Nov 21, 2014

### Orodruin

Staff Emeritus
There are three drops involved in the problem. One is just hitting the sink, one is just leaving the faucet, and one is in the air somewhere in between. The question asks you to locate this last drop. The implicit assumption being that drops leave the faucet at a constant rate.

3. Nov 21, 2014

### CWatters

eg The drops are equidistant in time but not space.

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