Answer:
B,C
Explanation:
In the law of magnetism, like poles repel and unlike poles attract. The north and South Pole attracts which makes B correct. The north and north or south and south poles repel.
In a compass ,the north end of a magnet is attracted to the south magnetic pole which is in close proximity to the geographic South Pole. This makes
Option c correct.
Answer:
(3) 53°
Explanation:
We want to measure the angle that the rains form with the vertical wind shield, so we have to measure the angle relative to the vertical. This means that we can write the following equation

where
is the speed of the rain, which travels vertically
is the speed of the bus, which travels horizontally
Substituting, we find

Answer: Option A: The spots on the balloon move away as the balloon is inflated.
one of the scientific models describes the galaxies are moving apart as the universe is expanding. This expansion theory came from the observation of red-shifted spectrum from all the directions indicating that the galaxies are moving away. This can be understood from the inflated balloon. Initially spots can be marked using a colored pen on the balloon.On inflating the balloon, it would be noticed that the spots on the balloon move away. Actually the position of the spots won't change, but the distance between the spots would expand. This is a good model to explain the expanding universe. The galaxies are neither moving in any random direction nor moving forward. So, rest of the options are not good models to explain the theory.
Hydrogen (H) has a molar mass of about 1.007 g/mol and has 1 electron.
Oxygen (O) has a molar mass of about 15.999 g/mol and has 8 electrons.
Then water (H₂O) has a total molar mass of about 18.015 g/mol and has 10 electrons.
30 g of water is the mass of
(30 g) × (1/18.015 mol/g) ≈ 1.66528 mol
of water. Recall that 1 mole is around 6.022 × 10²³ molecules (i.e. Avogadro's number). So 30 g of water is the mass of approximately 1.00285 × 10²⁴ molecules of water.
If each molecule contains 10 electrons, then 30 g of water contains 1.00285 × 10²⁵ ≈ 10²⁵ electrons.
Answer:
A combined wave of extra height will produce every other wave.
Explanation:
One wave Crest can catch up to another wave Crest if the group of waves are from different places.
Here the two group of waves have different wavelength but travelling together in the same direction so when they combine,they will produce every other wave.