Answer:
(i)
, (ii)
, (iii) 
Explanation:
(i)
and
represent the points where particle has a velocity of zero and spring reach maximum deformation, Given the absence of non-conservative force and by the Principle of Energy Conservation, the position where particle is at maximum speed is average of both extreme positions:

(ii) Maximum accelerations is reached at
and
.

(iii) Greatest net forces exerted on the particle are reached at
and
.

Answer:
Venus is only 95% the size of Earth, and 81% of its mass. With the smaller size and mass, the force of gravity pulling you on the surface is lower. To get your weight on Venus, just multiply your current weight by 0.9. That's why 100 pounds becomes 90 pounds
Answer:
a) F = 1.26 10⁵ N, b) F = 2.255 10³ N, c) F_ {soil} = 3078 N
Explanation:
For this exercise we will use the relationship between momentum and moment
I = Δp
F t = p_f -p₀
a) with stiff legs, final speed is zero, initial velocity is down
Ft = 0-p₀
F = m v / t
let's calculate
F = 84.0 6.82 / 4.56 10⁻³
F = 1.26 10⁵ N
b) bending the legs
let's calculate
F = 84.0 6.82 / 0.254
F = 2.255 10³ N
c) It is requested to calculate the force of the ground on the man
∑ F = F_soil -W
F_soil = F + W
F_ {soil} = 2.255 103 + 84 9.8
F_ {soil} = 3078 N
If I am reading this correct, the energy content would decrease for the liquid to solidify