1. Nov 18, 2004

### manjuj

Quentin claims that he can throw a dart at dartboard from distance of 2.0 m & hit 5 cm wide bullseye if he throws dart horizantally with speed of 15 m/s. He starts the throw at the same height as top of bullseye. See if Quentin is able to hit bullseye by calculating how far his shot falls from the bullseye's lower edge. THANKS IN ADVANCE!

2. Nov 18, 2004

### Galileo

Here's a way:
Use $$d=vt$$ to find the amount of time the dart flies.
Then use $$h=1/2gt^2$$ to find what distance it has fallen.

3. Nov 18, 2004

### manjuj

Dart problem

Thanks Galileo for your suggestion. I should have posted that I tried that and what I get is:

using x=vt, 2=15t, t=7.5 secs

y at 7.5 secs would be (using 1/2gt^2): -4.9 X 56.25 = -275.625

275.625 m below the throwing height doesnt make sense to me or does it mean that the answer is: Quentin will not be able to hit the bullseye. Thanks

4. Nov 18, 2004

### lalbatros

The time of flight you calculated is wrong.
It is actually much lower.
If 7.5 sec was correct, Quentin could have run faster than the dart.

5. Nov 18, 2004

### manjuj

Dart problem

Thank you alalbatros! I was dividing 15 by 2 instead of the other way around. It makes sense now. Thanks again.