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hyen84
Mar4-04, 06:41 PM
i need help with this 2 physics question..can someone help me please....thank you very much...which equation should i use...

1. A hot-air balloon is rising straight up with a speed of 5.00 m/s. A ballast bag is released from rest relative to the balloon when it is 2.95 m above the ground. How much time elapses before the ballast bag hits the ground?

2.After leaving the end of a ski ramp, a ski jumper lands downhill at a point that is displaced 66.7 m horizontally from the end of the ramp. His velocity, just before landing, is 18.3 m/s and points in a direction 32.2 degrees below the horizontal. Neglecting air resistance and any lift that he experiences while airborne, find (a) the magnitude and (b) the direction of his initial velocity when he left the end of the ramp.

Doc Al
Mar4-04, 07:08 PM
Originally posted by hyen84
i need help with this 2 physics question..can someone help me please....thank you very much...which equation should i use...

Why don't you give them a try and show us what you know?

Here's a hint. One equation for uniformly accelerated motion is:
Y = Y_i + V_{y,i}T + \frac{1}{2}aT^2

For the second problem, did you leave any information out?

Tom McCurdy
Mar4-04, 09:47 PM
Well We did a lot of calculations like your second problem in my class... So many in fact that I wrote a program that does all the calcualtions and can add stuff like friction... however I seem to have misplaced my caclulator right now. When I find it i will try to remember to come back to help.

cookiemonster
Mar4-04, 10:48 PM
Heh, you really don't need to write a program to do this kind of stuff.

I think you should just try to apply the equation Doc Al has kindly posted.

cookiemonster

Tom McCurdy
Mar6-04, 12:12 AM
The program was written by myself for myself... In order to program something you need to know it inside and outside. I know how to do these problems by hand as well cookiemonster.

cookiemonster
Mar6-04, 12:34 AM
I'd argue that point. You don't need to know something inside and out in order to convince a calculator to do it for you. You just need a formula.

It's not my contention, though, that you don't know how to solve these kinds of problems. I just don't really understand why one would write a program for a simple problem such as this. A program for Fourier Series or Newton's Approximation Method (I've personally written programs for each of these, and quite a few others) I can understand.

cookiemonster

hyen84
Mar6-04, 11:54 AM
Please guys don't argue..i don't want it to be b/c of me asking for help that turn into an argument...if the program work for Tom McCurdy, thats great..but i like to do things hand on..so..i'm doing it using formulas... thanks guys for your help...