Parachute physics problem. need help.?
When a parachute opens, the air exerts a large drag force on it. This upward force is initially greater than the weight of the sky diver and, thus, slows him down. Suppose the weight of the sky diver is 942 N and the drag force has a magnitude of 1115 N. The mass of the sky diver is 96.1 kg. What are the magnitude and direction of his acceleration?
Comments
Set down as positive since this is the direction of his motion....
F = 942 - 1115 = -173 N
F = ma
-173 = (96.1)a
a = -173 / 96.1
a = -1.80 m/s²
His motion is down, but his acceleration is up, meaning he is slowing down.
The net force is 1115up - 942down = 173N up
Fnet=ma so a=Fnet/m = 173N/96.1=1.80m/s^2 up