The first one is C. Hope this helps!! If you need anymore help just message me and I will try to get back to you quickly and help in any way i can!
Answer:
a) 
s
b) 3.41 mm
Explanation:
a)
We take the speed of light, c = 
m/s and the refractive index of glass as 1.517.
Speed = distance/time
Time = distance/speed
Refractive index, n = speed of light in vacuum / speed of light in medium
b)
We take the refractive index of water as 1.333.
Speed in water = speed in vacuum / refractive index of water
Distance = speed * time
d = 3.41 mm
Risk of not being able to reduce their weight
Answer:
Relative to the ground, the velocity of the aircraft is 240 km/hr
Explanation:
Relative velocity is different from normal velocity;
When 2 objects are moving in opposite directions towards each other, they will appear to be faster than they actually are;
This is known as the relative velocity;
The information tells us we have the aircraft moving 320 km/hr northwards relative to the wind;
The wind is in the opposite direction at 80 km/hr;
R = relative velocity of the aircraft
v = actual velocity of the aircraft
w = velocity of the wind
R = v + w
Note: if the wind was moving in the same direction, the formula would be R = v - w
320 = v + 80
v = 320 - 80
v = 240
The velocity relative to the ground is simply the actual velocity as the ground doesn't move;
So, relative to the ground, the velocity of the aircraft is simply 240 km/hr
Answer:
Most interstellar clouds are much bigger than our solar system.
Explanation:
An interstellar cloud refers:
- It is generally an accumulation of gas, plasma, and dust in our and other galaxies.
- It is basically a denser-than-average region of the interstellar medium (ISM).
Interstellar clouds can be large up to 106 solar masses
It is also often said to be the most massive entities in the galaxy.
Hence
we can say about Interstellar clouds,
They are much bigger than our solar system.
learn more about interstellar clouds here:
<u>brainly.com/question/14726563</u>
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