Stressing an equilibrium simply means that the physical properties in which already exists are balanced. Stress can be applied by either changing the pressure or the volume or temperature.
Answer:
k = 52.2 N / m
Explanation:
For this exercise we are going to use the conservation of mechanical energy.
Starting point. When it is 30 m high
Em₀ = K + U = ½ m v² + m g h
Final point. Right when you hit the water
= K_{e} = ½ k x²
in this case the distance the bungee is stretched is 30 m
x = h
as they indicate that there are no losses, energy is conserved
Em₀ = Em_{f}
½ m v² + m g h = ½ k h²
k = 
let's calculate
k = 
k = 52.2 N / m
Answer: 20m/s.
Explanation:
Remember the second Newton's law:
F = a*m
This is:
The net force acting on an object is equal to the mass of the object times the acceleration of the object.
In this case, we have a force of 5N pushing the object to the right.
We also have a force of 5N pushing the object to the left.
These forces act on opposite directions.
Then the net force will be equal to the difference of these forces, this is:
F = 5N - 5N = 0N
Then the net force is 0N, then we have:
0N = m*a
0N/m = 0m/s^2 = a
This means that the acceleration of the object is 0, then the velocity of the object does not change.
This means that if the object was moving at a constant velocity of 20m/s, the velocity of the object will still be equal to 20m/s. (because the net force acting on the object is zero)
To solve this problem we will apply the concepts related to the Impulse which can be defined as the product between mass and the total change in velocity. That is to say
Here,
m = mass
Change in velocity
As we can see there are two types of velocity at the moment the object makes the impact,
the first would be the initial velocity perpendicular to the wall and the final velocity perpendicular to the wall.
That is to say,
El angulo dado es de 45° y la velocidad de 25, por tanto
The change of sign indicates a change in the direction of the object.
Therefore the impulse would be as
The negative sign indicates that the pulse is in the opposite direction of the initial velocity.
Answer:
1.98 m/s
Explanation:
To solve this, we would be using the law of conservation of energy, i.e total initial energy is equal to total final energy.
E(i) = E(f)
mgh = ½Iw² + ½mv²
Recall, v = wr, thus, w = v/r
Also, I = ½mr²
I = 0.5 * 5 * 2²
I = 10 kgm²
Remember,
mgh = ½Iw² + ½mv²
Substituting w for v/r, we have
mgh = ½I(v/r)² + ½mv²
Now, putting the values in the equation, we have
5 * 9.8 * 0.3 = ½ * 10 * (v/2)² + ½ * 5 * v²
14.7 = 1.25 v² + 2.5 v²
14.7 = 3.75 v²
v² = 14.7/3.75
v² = 3.92
v = √3.92
v = 1.98 m/s
Thus, the speed is 1.98 m/s
