Answer:
40 Kpa
Explanation:
150 cm2 = 0.015 m2
Consider this situation: Four ropes, each attached to the end
1 answer:
The forces acting on the elevator are:
Gravity force
Tension force
Air resistance
Explanation:
Let's go through each of the forces listed and see which ones are acting on the elevator.
- Normal force: NO. The normal force is a force exerted by a surface whenever there is another object "pushing" on it. For instance, when a box is at rest on a table, the box is "pushing" on the table (due to its weight), and the table "pushes back" on the box, upward, in order to balance its weight: this is the normal force. In this case, the elevator is lifted, so it is not pushing on anything, therefore there is no normal force.
- Gravity force: YES. The force of gravity acts on every object located in the gravitational field of the Earth; it pulls downward, and its magnitude is
, where m is the mass of the object and g is the acceleration of gravity.
- Applied force: NO. Here there is no applied force, since there is nobody "pushing" or "pulling" the elevator.
- Friction force: NO. As we are considering the forces on the elevator, and the elevator is not sliding against any surfaces, there is no force of friction. (The force of friction acts whenever there are two surfaces sliding against each other, which is not the case here)
- Tension force: YES. The tension force is the force exerted by a rope or a string when pulling an object. In this case, there are four ropes pulling the elevator, therefore there are 4 forces of tension acting on the elevator, upward.
- Air resistance: YES. As the elevator is moving through the air, the interaction between the molecules of air with the surface of the elevator produces a force (called air resistance) that "resists" the motion of the elevator, therefore pushing downward. However, the magnitude of this force is negligible in this case.
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Answer:
Power is the rate at which energy is transformed.
The SI unit of power is the watt.
Power is the rate at which work is done.
Explanation:
In this question we have to choose the statements related to Power that are True.
In this sense, Power is the speed with which work
is done. Its unit is Watts (
), being
.
Power is mathematically expressed as:
Where is the time during which work
is performed.
On the other hand, the Work done by a Force
refers to the release of potential energy from a body that is moved by the application of that force to overcome a resistance along a path. It is a scalar magnitude, and its unit in the International System of Units is the Joule (like energy). Therefore, 1 Joule is the work done by a force of 1 Newton when moving an object, in the direction of the force, along 1 meter (
).
So, according to this explanation, the true statements are:
Power is the rate at which energy is transformed.
The SI unit of power is the watt.
Power is the rate at which work is done.
Explanation:
Formula for steady flow energy equation for the flow of fluid is as follows.
Now, we will substitute 0 for both and
, 0 for w, 334.9 kJ/kg for
, 2726.5 kJ/kg for
, 5 m/s for
and 220 m/s for
.
Putting the given values into the above formula as follows.
q = 6597.711 kJ
Thus, we can conclude that heat transferred through the coil per unit mass of water is 6597.711 kJ.