Answer:
The maximum speed of sonic at the bottom of the hill is equal to 19.85m/s and the spring constant of the spring is equal to (497.4xmass of sonic) N/m
Energy approach has been used to sole the problem.
The points of interest for the analysis of the problem are point 1 the top of the hill and point 2 the bottom of the hill just before hitting the spring
The maximum velocity of sonic is independent of the his mass or the geometry. It is only depends on the vertical distance involved
Explanation:
The step by step solution to the problem can be found in the attachment below. The principle of energy conservation has been applied to solve the problem. This means that if energy disappears in one form it will appear in another.
As in this problem, the potential and kinetic energy at the top of the hill were converted to only kinetic energy at the bottom of the hill. This kinetic energy too got converted into elastic potential energy .
x = compression of the spring = 0.89
Answer: Car collide with man
Explanation:
Given
Speed of car is 
Distance of the man from the car is 
Reaction time 
Rate of deceleration 
Distance traveled in the reaction time 
Net effective distance to cover 
Distance required to stop the car

Require distance is more than that of net effective distance. Hence, car collides with the man.
Answer:
The free body diagram is attached.
Explanation:
A force of 31[N] to the east, the second force goes to the south and it is equal to 28[N], the third force goes to the west and it is equal to 39 [N].
We can consider the crate as a particle. And all the forces are acting over the particle.
Assuming ideal conditions, Boyle's law says that
<em>P₁ V₁ </em>= <em>P₂</em> <em>V₂</em>
where <em>P₁ </em>and <em>V₁</em> are the initial pressure and temperature, respectively, and <em>P₂</em> and <em>V₂</em> are the final pressure and temperature.
So you have
(455 mm Hg) (56.5 m³) = (632 mm Hg) <em>V₂</em>
==> <em>V₂</em> = (455 mm Hg) (56.5 m³) / (632 mm Hg) ≈ 40.7 m³
Acceleration = force / mass = 500/45 = 11.1 m/s^2