Observer A is moving inside the train
so here observer A will not be able to see the change in position of train as he is standing in the same reference frame
So here as per observer A the train will remain at rest and its not moving at all
Observer B is standing on the platform so here it is a stationary reference frame which is outside the moving body
So here observer B will see the actual motion of train which is moving in forward direction away from the platform
Observer C is inside other train which is moving in opposite direction on parallel track. So as per observer C the train is coming nearer to him at faster speed then the actual speed because they are moving in opposite direction
So the distance between them will decrease at faster rate
Now as per Newton's II law
F = ma
Now if train apply the brakes the net force on it will be opposite to its motion
So we can say
- F = ma

so here acceleration negative will show that train will get slower and its distance with respect to us is now increasing with less rate
It is not affected by the gravity because the gravity will cause the weight of train and this weight is always counterbalanced by normal force on the train
So there is no effect on train motion
Answer:
ω = 0.05 rad/s
Explanation:
We consider the centripetal force acting as the weight force on the surface of the cylinder. Therefore,

where,
ω = angular velocity of cylinder = ?
g = required acceleration = 9.8 m/s²
r = radius of cylinder = diameter/2 = 5.9 mi/2 = 2.95 mi = 4023.36 m
Therefore,

<u>ω = 0.05 rad/s</u>
magnetic materials will produce magnetic field near it
All magnets are made up of small magnet type atoms which are known as domains
These all atoms will align itself so that they all produce strong magnetic field along the axis
this magnetic field will become more strong as more number of atoms are aligned.
Now if we break the magnet into small piece then the magnetic field strength will start decreasing and at the end when only one atom will remain then the magnetic field strength will reduce to the field of one atom only.
Answer:
Collinear is when points are in the same straight line but coplanar is when points are all on the same plane.
Answer:
C) specific heat capacity
Explanation:
As we know that heat given to the system to change the temperature is given as

here we know that
Q = thermal energy given to the system
s = specific heat capacity of the system
= change in temperature
so here we know that

here we know that heat given to the two cubes is of same amount as well as the mass is same but the final temperature is different because of the specific heat capacity (s)
So correct answer would be
C) specific heat capacity