Answer:
1) Used in optical instruments such as telescopes.
2) Used to form mirages
Explanation:
1) Perhaps the simplest example of this is the astronomical refractor telescope with a right-angle eyepiece holder. Astro scopes mostly point at things high in the sky, but it is inconvenient to place your eye low to look up through the scope, so the light path is bent 90 degrees just before the eyepiece. This can be done with a mirror, but using a simple 45 degree prism (internal angles 45, 45, and 90 degrees) will do the 90 degree bend more efficiently.
2) So when a light pass from cold air to hot air light tends to bend from its path which is known as refraction. As the light get refracted it reaches to a point where the light tends to form 90 degree angle.
Answer:
Explanation:
Given that,
A portable music player is operating with 4 cell batteries connected in series, and each cell has a P.D of 1.5V.
Then,
Total potential difference is
P.D_total = V1 + V2 + V3 + V4
P.D_total = 1.5 + 1.5 + 1.5 + 1.4
P.D_total = 6V.
The music player provides a resistance of 15,000Ω
R = 15,000Ω
We want to find the current (I) flowing through the music player?
Using ohms law
V = IR
Where
V is the potential difference
I is the current
R is the resistance
Therefore,
I = V/R
I = 6 / 15,000
I = 4 × 10^-4 A
I = 0.4 × 10^-3 A
I = 0.4 mA.
So, 0.4mA is passing through the music player
<span>The answer is Music Mnemonics.
Mnemonic is originally coming from the Ancient Greek word means “memory”. It is the study and development of systems for improving and assisting the memory. Mnemonic techniques are more specific memory aids. Music Mnemonic is a way we used to remember song lyrics and rhythmic movement.</span>
Answer
given,
mass of satellite = 545 Kg
R = 6.4 x 10⁶ m
H = 2 x 6.4 x 10⁶ m
Mass of earth = 5.972 x 10²⁴ Kg
height above earth is equal to earth's mean radius
a) satellite's orbital velocity
centripetal force acting on satellite = 
gravitational force = 
equating both the above equation



v = 5578.5 m/s
b) 


T = 14416.92 s

T = 4 hr
c) gravitational force acting


F = 5202 N