# Hot air balloon homework

1. Sep 20, 2004

### mikep

can someone help me with this problem?
A hot air balloon has just lifted off and is rising at the constant rate of 2.4 m/s. Suddenly, one of the passengers realizes she has left her camera on the ground. A friend picks it up and tosses it straight upward with an initial speed of 11.2 m/s. If the passenger is 2.5 m above her friend when the camera is tossed, how high is she when the camera reaches her on its way up?

i tried to first find the time, which i think is 0.88s. but i'm not sure. can someone please help

2. Sep 21, 2004

### NateTG

Well at the time the height of the camera and the height of the baloon should be equal, right, so we can calculate both, and see if they're equal:

Tossed camera height after 0.88s:
$$11.2 (0.88) - \frac{1}{2} 9.81 \times 0.88^2 \approx 6$$
Ballon height after 0.88s:
$$2.5+2.4 (0.88) \approx 4.5$$

I'm not sure where your error is.
Calculating the time first should get you to the right answer.

If you're not sure how to proceed, you should be able to use what I wrote above to set up an equation.