A sandbag is released from a rising air balloon and hits the ground 7.00 seconds later. From what height was the sandbag dropped from if at the moment of release the balloon was traveling upward at 3.00 m/s?
A) 219 m
B) 240 m
C) 459 m
D) 261 m
E) 55 m

Question

Quizplus · Accepted Answer

The sandbag's initial upward velocity is 3.00 m/s. It falls for 7.00 seconds, so its displacement is:$$d = vi*t + 1/2*a*t^2$$$$d = 3.00 m/s * 7.00 s + 1/2 * -9.80 m/s^2 * (7.00 s)^2$$$$d = 21.0 m - 245 m$$$$d = -224 m$$The negative sign indicates that the sandbag is below its starting point. So the height from which the sandbag was dropped is 224 m.

A Sandbag Is Released from a Rising Air Balloon and Hits