Answer:
The magnitude of the torque due to gravity if it is supported at the 28-cm mark is 0.5 N-m.
Explanation:
Given that,
Mass of the meter stick, m = 0.3 kg
Center of mass is located at its 45 cm mark.
We need to find the magnitude of the torque due to gravity if it is supported at the 28-cm mark. Torque acting on the object is given by :

or

So, the magnitude of the torque due to gravity if it is supported at the 28-cm mark is 0.5 N-m.
Remember opposites attract and same charges repel each other.
Object A= negatively charged.
Object A and B attract so B must be positively charged.
Object B and C repel so because B is positively charged C must also be positively charged.
Object C and D attract and because C is positively charged, D must be negatively charged.
Answer:
The energy of these two photons would be the same as long as their frequencies are the same (same color, assuming that the two bulbs emit at only one wavelength.)
Explanation:
The energy
of a photon is proportional to its frequency
. The constant of proportionality is Planck's Constant,
. This proportionality is known as the Planck-Einstein Relation.
.
The color of a beam of visible light depends on the frequency of the light. Assume that the two bulbs in this question each emits light of only one frequency (rather than a mix of light of different frequencies and colors.) Let
and
denote the frequency of the light from each bulb.
If the color of the red light from the two bulbs is the same, those two bulbs must emit light at the same frequency:
.
Thus, by the Planck-Einstein Relation, the energy of a photon from each bulb would also be the same:
.
Note that among these two bulbs, the brighter one appears brighter soley because it emits more photons per unit area in unit time. While the energy of each photon stays the same, the bulb releases more energy by emitting more of these photons.
You would be correct.
Because you have only JUST released the arrow, and how close he is to the target, it would have the same amount of energy when it strikes the target. Yes, the kinetic energy would be destroyed when you hit the target but not right away. And yes, the potential energy would also be destroyed once you release the arrow, but it goes straight back once it stops moving, aka when it hits the target, although it has only just stopped moving.
Hope this helps!