Answer:
4. B and D
Explanation:
Two points along a transverse wave (such as the one in the figure) are said to be in phase when:
- the vertical position of the two points is the same
- The oscillation of the wave is going in the same way for both points
Basically, we say that two points are in phase when they are separated by a complete cycle (one complete oscillation) of the wave.
For this wave, we see that point B and C have same displacement, but they are not in phase since in B the oscillation is going down while in C is going up.
Instead, B and D are in phase, because they are separated by one complete cycle: both points have same displacement and the oscillation is going in the same way for both of them.
Answer:
0.686 g of ice melts each second.
Solution:
As per the question:
Cross-sectional Area of the Copper Rod, A = 
Length of the rod, L = 19.6 cm = 0.196 m
Thermal conductivity of Copper, K = 
Conduction of heat from the rod per second is given by:
where
= temperature difference between the two ends of the rod.
Thus
Now,
To calculate the mass, M of the ice melted per sec:
where
= Latent heat of fusion of water = 333 kJ/kg
-- 'Ca' (Calcium) is an element.
-- The proton has a positive charge.
-- Nuclear fusion results in the synthesis of atoms of new elements.
-- H₂O (water) is a chemical compound.
-- Nuclear fission is a decay of the nucleus.
-- The atomic number of an element is the number of protons
in each atom of it.
-- I suppose you're using the Greek letter <span>η ('eta', not 'nu')
to represent the neutron.
-- I suppose you're using ' e ' to represent the electron.
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Sound spreads through some kind of medium. Most of the time the medium is usually air. Sound can go through walls, like when you are playing really loud music and the neighbors tell you its to loud, you can't block it because it can travel through objects. Light does not need a medium to travel with. if you put a light in a room with no windows and no cracks, and you seal off the door the light can't escape that room, but if you did the same thing with sound it would travel trough the walls.
