Answer:
a. the core will spin faster.
Explanation:
By law of conservation of angular momentum
(mvR)i= (mvR)f
m= mass of star
v= speed of star
R= radius of star
i= initial
f= final
since, size(R) of the star is reduced by factor of 10,000 and mass remains the same, the velocity must increase by the same factor to keep the angular momentum conserved.
Hence, a. the core will spin faster.
Exercise is the activity and fitness is a lifestyle and done with time
Answer:
The magnetic field in the System is 0.095T
Explanation:
To solve the exercise it is necessary to use the concepts related to Faraday's Law, magnetic flux and ohm's law.
By Faraday's law we know that
Where,
electromotive force
N = Number of loops
B = Magnetic field
A = Area
t= Time
For Ohm's law we now that,
V = IR
Where,
I = Current
R = Resistance
V = Voltage (Same that the electromotive force at this case)
In this system we have that the resistance in series of coil and charge measuring device is given by,
And that the current can be expressed as function of charge and time, then
Equation Faraday's law and Ohm's law we have,
Re-arrange for Magnetic Field B, we have
Our values are given as,
Replacing,
Therefore the magnetic field in the System is 0.095T
Answer:
Only option A is correct
Explanation:
From the concept of Doppler effect, only speed matters. Thus, the faster a vehicle is moving, the closer together the sound waves get compressed and the higher the frequency. For example, for a very fast vehicle traveling at the speed of sound; the compressions are all right on top of each other. Thus, faster speed means closer compressions and higher frequencies. Hence, option only option A must be true because X is a higher frequency and so it must be going faster. The distance to the person will affect the volume but will not the pitch so Option B is not correct. Option C too is not correct because It doesn’t matter whether you are speeding up or slowing down, it only matters who is going faster. For example, from option c concept, if truck X was going 10 m/h and speeding up while truck Y was going 50 mph and slowing down, it would not meet the requirement that X has a higher frequency because only actual speed matters, not what is happening to that speed. Thus only option A is the correct answer