PDA

View Full Version : Speed and distance


jacklin
Sep 23, 2007, 05:45 PM
A hot air balloon is rising up with a constant speed of 5m/s. When the balloon is 2m above the ground, the balloonist accidentally drops a compass over the side.

Question: 1. How much time elapse before it hit the ground?
2. what is it speed before it hit the ground?
3. how high above the ground is the balloon when the compass hit the ground?

chris89
Sep 23, 2007, 08:42 PM
Use the kinematic equations to work it out.
For question one use: d = vi*t + (a*t^2)/2
For two use v=a*t (using t calculated from question 1)
For three use the time calculated in 1) multiply by the constant speed of the balloon, and add 5.
where v =velocity
vi initial velocity
a= acceleration(due to gravity in this case, which is 9.8m/s^2
d= distance
t=time