Displacement = 0, assuming that he runs back to original position
Average velocity is displacement/ time, since displacement =0, velocity is also 0
solution:
We know v0 = 0, a = 9.8, t = 4.0. We need to solve for v
so,
we use the equation:
v = v0 + at
v = 0 + 9.8*4.0
v = 39.2 m/s
Now we just need to solve for d, so we use the equation:
d = v0t + 1/2*a*t^2
d = 0*4.0 + 1/2*9.8*4.0^2
d = 78.4 m
Explanation:
The reading on the scale is
W = m(g + a)
= (77 kg)(9.8 m/s^2 + 2 m/s^2)
= 908.6 N
The FREQUENCY of light remains unchanged once it leaves the source.