Posted by Vanessa on .
A weather balloon carrynig a data measurement(DM) is rising quickly at a constant velocity, U. when its 60m above ground, balloon pops and the dm experiences freefall. It reaches ground 4 seconds after the balloon pops. If DM set hits ground at speed greater than 40 ms1 it will break.
Explain whether the DM set broke. showing your working clearly.
State whether the dm set would have broke if the weather balloon was moving at a constant velocity of U if it pops

Physics 
Steve,
the height of the DM after the balloon pops is given by
y(t) = 60 + Ut  4.9t^2
If y(4) = 0, then
60+4U78.4 = 0
U = 4.6
The speed of the DM is given by
v(t) = U9.8t
v(4) = U39.2
So, as long as U > 0.8, the DM will hit the ground with v > 40m/s and will not break.