Answer:
its a shield that can protect us from super hot rays and all though ita not that strong atleast we wont get burned to death lol :)
Answer:
Condensation causes dew to form on blades of grass. This is because the water molecules react to the grass when it is heated, and the surroundings became cool. The molecules would bring to calm and turn to liquid.
Explanation:
I just took the test
Answer:
b) Betelgeuse would be 
times brighter than Sirius
c) Since Betelgeuse brightness from Earth compared to the Sun is 
the statement saying that it would be like a second Sun is incorrect
Explanation:
The start brightness is related to it luminosity thought the following equation:
(1)
where 
is the brightness, 
is the star luminosity and 
, the distance from the star to the point where the brightness is calculated (measured). Thus:
b) 
and 
where 
is the Sun luminosity (
) but we don't need to know this value for solving the problem. 
is light years.
Finding the ratio between the two brightness we get:
c) we can do the same as in b) but we need to know the distance from the Sun to the Earth, which is 
. Then
Notice that since the star luminosities are given with respect to the Sun luminosity we don't need to use any value a simple states the Sun luminosity as the unit, i.e 1. From this result, it is clear that when Betelgeuse explodes it won't be like having a second Sun, it brightness will be 5 orders of magnitude smaller that our Sun brightness.
Answer:
When you blow into a tuba the air vibrates very slowly.
Explanation:
Tuba is a buzz instrument ie sound is produced in it with the help of lip vibration . It is the lowest pitched musical instrument in the brass family .
Due to absence of resonance in it , it produces music of lowest pitch , So when one blows into it the air column of the instrument vibrates very slowly producing low pitched sound.
Answer:
276.135 J
Explanation:
Given that:
mass of Fe = 30.0 g
initial temperature = 24.5°C
final temperature = 45.0°C
specific heat of Fe = 0.449 J/g°C
We can determine the thermal energy added by using the formula;
Q = mcΔT
Q = 30.0g × 0.449 J/g°C × (45.0 - 24.5)°C
Q = 276.135 J
