Question

a sky diver jumps out of a plane that is 3000m above ground with an initial upward speed of 6m/s she free falls for 20s (assume there is no wind at this time)before pulling the cord to activate the parachute she then falls to the ground at a constant downward speed of 5m/s, how far did she fall before activating the parachute, and how long was she in the air altogether from the moment she left the plane to the moment she touched the ground

Answer 1

Let us divide the ques into 3 parts: the initial v,the 20s descent,the final v,since distance from ground level=3000m.

Answer 2

Let us divide the ques into 3 parts: the initial v,the 20s descent,the final v,since distance from ground level=3000m,

Answer 3

the 1st part:using V=6 v*v/2g=h,36/20=1.8m,new distance(diver) from ground=3000+1.8=3001.8m.

Answer 4

2nd part:20s descent. using a=v-u/t,where a=10.t=20,and u=0,v=200,using v*v/2g=h,200*200/20=2000new h=3001.8-2000

Answer 5

Since final h=1001.8m,find the time,t=h/v, 1001.8/5m/s=200.36.total time=200.36+20+0.6=220.96get 0.6 from h=1.8