Answer:
I'm not completely sure, but I believe the first and third of the three are mechanical.
Explanation:
Chemical potential isn't moving or about to go into motion. It can't be mechanical.
Answer:
If the canoe heads upstream the speed is zero. And directly across the river is 8.48 [km/h] towards southeast
Explanation:
When the canoe moves upstream, it is moving in the opposite direction of the normal river current. Since the velocities are vector (magnitude and direction) we can sum each vector:
Vr = velocity of the river = 6[km/h}
Vc = velocity of the canoe = -6 [km/h]
We take the direction of the river as positive, therefore other velocity in the opposite direction will be negative.
Vt = Vr + Vc = 6 - 6 = 0 [km/h]
For the second question, we need to make a sketch of the canoe and we are watching this movement at a high elevation. So let's say that the canoe is located in point 0 where it is located one of the river's borders.
So we are having one movement to the right (x-direction). And the movement of the river to the south ( - y-direction).
Since the velocities are vector we can sum each vector, so using the Pythagoras theorem we have:
![Vt = \sqrt{(6)^{2} +(-6)^{2} } \\Vt=8.48[km/h]](https://tex.z-dn.net/?f=Vt%20%3D%20%5Csqrt%7B%286%29%5E%7B2%7D%20%2B%28-6%29%5E%7B2%7D%20%7D%20%5C%5CVt%3D8.48%5Bkm%2Fh%5D)
Efficiency
Explanation:
Efficiency is a ratio/percentage that is useful in comparing the energy transferred by a device to the total energy supplied to it.
Percentage efficiency =
x 100
- As with most system, none is 100% efficient.
- During energy is transferred some are lost and only a little portion is used in doing actual work by the machine.
- This validates the third law of thermodynamics which proposes that no system is 100% efficient.
- A 100% efficiency implies total energy input is used doing all the work.
- This is impossible. The bulk of the energy goes into heating the system.
learn more:
Third law of thermodynamics brainly.com/question/3564634
#learnwithBrainly
Answer: D. The force and displacement are in the same direction.
Explanation:
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 with distance
.
Work is a scalar magnitude, and its unit in the International System of Units is the Joule (like energy).
Now, when the applied force is constant and the direction of the force and the direction of the displacement are <u>parallel</u>, the equation to calculate it is:
(1)
When they are not parallel, both directions form an angle, let's call it
. In that case the expression to calculate the Work is:
(2)
When the force and displacement are perpendicular to each other,
and <u>no work is done</u>.
Answer: Whenever the temperature is high, the air pressure is low.
Explanation:As the temperature rises, the air gets heated, expands, and becomes lighter. … As a result, the air pressure in such areas decreases.