Answer:
Decreases the time period of revolution
Explanation:
The time period of Cygnus X-1 orbiting a massive star is 5.6 days.
The orbital velocity of a planet is given by the formula,
v = √[GM/(R + h)]
In the case of rotational motion, v = (R +h)ω
ω = √[GM/(R + h)] /(R +h)
Where 'ω' is the angular velocity of the planet
The time period of rotational motion is,
T = 2π/ω
By substitution,
<em>T = 2π(R +h)√[(R + h)/GM] </em>
Hence, from the above equation, if the mass of the star is greater, the gravitational force between them is greater. This would reduce the time period of revolution of the planet.
Answer:
hence option A is correct
Explanation:
heat required from -9°C to 0°C ice = mass × specific heat of ice ×change in temperature
heat required from -9°C to 0°C ice = 7×2100×9 =132300 J =0.1323 MJ
( HERE SPECIFIC HEAT OF ICE IS A CONSTANT VALUE OF 2100
J/(kg °C )
heat required from 0°C ice to 0°C water = mass× specific heat of fusion of ice
= 7×3.36×10^5
= 2.352 × 10^6 J
= 2.352 MJ
TOTAL HEAT ENERGY REQUIRED = 0.1323 MJ +2.352 MJ
= 2.4843 MJ
hence option A is correct
An electric circuit is anything in which electric current flows. Typically it refers to things with wiring like the electronics in your phone, but it can be made of anything that conducts electricity.
Say you have a battery, it basically has a bunch of electrons under a potential (think of gas in a tank under pressure), but the only way for the electrons to move is to move through a conductor, which are molecules with loosely held electrons. If you take a copper wire and touch each end to the two terminals you’ve completed an electric circuit because the electrons can now flow. But you can also put things partway through the wire like a lightbulb, which when the electrons run through it generates light.
Answer:
The energy level is 5.
Explanation:
Given that,
n = 3
l = 2
We know that,
l shows the number of sub-shells and define the number of angular nodes.
n shows the number of electron shell.
is a quantum number. It is define the number of energy level in a sub-shells .
is define the spin of the electron.
So, The quantum number is
is 
and 
for every energy level.
The energy level is 5.
Hence, The energy level is 5.
<u>Answer:</u>
<em>The initial distance between the trains is 1450 m.
</em>
<u>Explanation:</u>
In the question two trains are of equal length 400 m and moves at a uniform speed of 72 km/h. train A is moving ahead of train B. If the train B has to overtake train A it should accelerate.
Train B’s acceleration is 
and it accelerated for 50 seconds.
<em>
</em>
<em>t=50 s
</em>
<em>initial speed u=72km/h
</em>
<em>we have to convert this speed into m/s </em>
<em>
</em>
<em>Distance covered in accelerating phase 
</em>
<em>
</em>
<em>
</em>
If a train is just behind another, the distance covered by the train located behind during overtaking phase will be equal to the sum of the lengths of the trains.
<em>Here length of train A+length of train 
</em>
<em>Hence the initial distance between the trains = 
</em>
