Answer:
equation of motion:
net force=weight-drag
m*(dv/dt)=m*g-12*v
70*v'+12*v=70*9.8
solving for v(t),we get
v(t)=343/6 - (343*exp(-(6*t)/35))/6
in t=10,,first jumper's velocity=46.87 m/s
for the second jumper,
equation of motion:
net force=weight-drag...