Answer:
The conservation of energy should be used to answer this question.
a)
At the position where the spring is unstretched, the elastic potential energy of the spring is zero.

since
and
is equal to zero.

The roots of this quadratic equation can be solved by using discriminant.


We should use the positive root, so
x = 0.292 m.
b)
We should use energy conservation between the point where the spring is momentarily at rest, and the point where the spring is unstretched.

since the kinetic energy at point 2 and the potential energy at point 3 is equal to zero.

Explanation:
In questions with springs, the important thing is to figure out the points where kinetic or potential energy terms would be zero. When the spring is unstretched, the elastic potential energy is zero. And when the spring is at rest, naturally the kinetic energy is equal to zero.
In part b) the cookie slides back to its original position, so the distance traveled, x, is equal to the distance in part a). The frictional force is constant in the system, so it is quite simple to solve part b) after solving part a).
Answer:
a. 
b. 
Explanation:
Given:



The runner force average to find given the equations
a.




b.
Work done by the system by this force so





Answer:
Correct answer: The fourth claim
Explanation:
No claim is most accurate but if you have to choose the best from the bad one, it's fourth - Its height decreased as its motion increased.
The potential energy depends from height Ep = m g h and kinetic
energy depends besides mass from velocity (motion) Ek = m v²/ 2
God is with you!!!
The acceleration is defined as the rate of change of velocity.
So, if the acceleration is zero, this means that the rate of change of velocity is zero, which also means that the body is moving with constant velocity.
Since we are given that the net forces acting on the body is zero, this means that the body is at equilibrium
Based on this:
<span>All forces on the bullets cancel so that the net force on a bullet is zero, which means the bullet has zero acceleration and is in a state known as equilibrium.
Note that if this constant velocity is equal to zero, then the body would be at rest (not moving)</span>