5-108. Tiny Tompfind, a man of mass 72 kg, jumps (from rest) from
a table 92 cm to the floor below. As he lands, he bends his knees so
that
he decelerates over a distance of 35 cm.
(a) What is Tiny's speed just as he hits the floor?
(b) As he decelerates, what is the magnitude of the force exerted on
him by the floor?
Correct
In fact any of A, B or C are satisfactory since nothing in the
problem involves the x direction. If we choose (B) then the motion
takes
place in the + direction.
We need his speed just before he hits the floor. Which Galilean
equation
is useful?
(A) vy = v0y
+ ayt
(B) y = v0yt
+ (1/2)ayt2
(C) vy2
= v0y2 + 2ayy