The luminosity is how bright an celestial body is.
The answer is A.) decrease.
Take pushing a box for example. You push your hardest but then give out, still trying to push. You're doing less work than what you started with.
Answer:
D,E,F
Explanation:
d. Earth's geographic north pole is actually a magnetic south pole.
e. The south poles of two bar magnets will repel each other.
f. The north pole of a bar magnet will attract the south pole of another bar magnet.
In a magnetic field like poles repel and unlike poles attract each other. The like poles which is south to south or north to north repel each other and the unlike poles which is north to south or south to north attract each other which makes E and F correct.
A is correct because compasses points to the North Pole when places in the Southern Hemisphere.
Answer:
13.5 ms
Explanation:
The sound wave travels with uniform motion in both cases, so the time taken to cover a distance d is given by:
where
d is the distance to cover
v = 340 m/s is the speed of sound in air
So for the people across the newsroom,
d = 4.7 m
So the time taken is
The radio waves instead travels with uniform motion at the speed of light:
So the time taken for them is
where
d = 82 km = 82,000 m
is the distance of the people who are 82 km away. Substituting,
Therefore, the difference in time is
As the bright sun shines upon the water, the water slowly dissapears. This is an example of physical change because here the water is just transformed into water vapour. So only the state and the shape of the substance has changed. Its originality remains absolutely intact. In the second case where the same sunlight gives energy to the surrounding plants to convert water and carbon dioxide into sugar and oxygen gas, it is a chemical change. here new substances are formed and the identity of the original substances are lost.In chemical reactions, the mass of the product will always be the same as the mass of the reactants.