The Sun's gravitational pull keeps our planet orbiting the Sun <span>in a nice nearly-circular orbit.</span>
        
             
        
        
        
<span>the ratio of the force produced by a machine to the force applied to it, used in assessing the performance of a machine. I would say the answer is D, but i'm not sure. :)</span>
        
             
        
        
        
We call "terminal velocity" the constant speed of a falling body 
when it is no longer accelerating.
We know that if a body is not accelerating, then the net force 
on it is zero.
From the question, we know that the downward force of gravity 
on the skydiver is 800 N.
If the 800 N downward plus the air resistance upward add up 
to zero, then the air resistance upward must also be 800 N.
        
                    
             
        
        
        
Use this equation 
Distance(s)=speed(v)•time(t)
Given,req-soln 
1.
S=10cm=0.1m
t=4sec
V=s/t=>0.1•10/4•10=>1/40=0.025
2.
V=0.1m/s
t=1.5 sec
S=vt =0.1•1.5=0.15