Answer:
P=627.47W
Explanation:
To solve this problem we have to take into account, that the work done by the winch is
the force, at least must equal the gravitational force
with force the tension in the cable makes the winch go up.
The work done is
To calculate the power we need to know what is the time t. But first we have to compute the acceleration
The acceleration will be
and the time t
The power will be
HOPE THIS HELPS!!
Answer:
Explanation:
This is a problem easily solve using energy conservation. As there are no non-conservative forces, we know that the energy is conserved.
When the spring is compressed downward, the spring has elastic potential energy. When the spring is relaxed, there is no elastic potential energy, but the pellet will have gained gravitational potential energy and kinetic energy. Lets see what are the terms for each of this.
<h3>Elastic potential energy</h3>We know that a spring following Hooke's Law has a elastic potential energy:
where is the displacement from the relaxed length and k is the spring's constant.
To obtain the spring's constant, we know that Hooke's law states that the force made by the spring is :
as we need 9.12 N to compress 4.60 cm, this means:
So, the elastic energy of the compressed spring is:
And when the spring is relaxed, the elastic potential energy will be zero.
<h3>Gravitational potential energy</h3>To see how much gravitational potential energy will the pellet win, we can use
where m is the mass of the pellet, g is the acceleration due to gravity and \Delta h is the difference in height.
Taking all this together, the gravitational potential energy when the spring is relaxed will be:
We know that the kinetic energy for a mass m moving at speed v is:
so, for the pellet will be
By conservation of energy, we know:
So