Answer:
b) Betelgeuse would be 
times brighter than Sirius
c) Since Betelgeuse brightness from Earth compared to the Sun is 
the statement saying that it would be like a second Sun is incorrect
Explanation:
The start brightness is related to it luminosity thought the following equation:
(1)
where 
is the brightness, 
is the star luminosity and 
, the distance from the star to the point where the brightness is calculated (measured). Thus:
b) 
and 
where 
is the Sun luminosity (
) but we don't need to know this value for solving the problem. 
is light years.
Finding the ratio between the two brightness we get:
c) we can do the same as in b) but we need to know the distance from the Sun to the Earth, which is 
. Then
Notice that since the star luminosities are given with respect to the Sun luminosity we don't need to use any value a simple states the Sun luminosity as the unit, i.e 1. From this result, it is clear that when Betelgeuse explodes it won't be like having a second Sun, it brightness will be 5 orders of magnitude smaller that our Sun brightness.
low speed means non relativistic.
the velocities relative to an observer outside the train are added.
51 m/s.
Were ita light wave, rather than Emma, the speed wold not depend on the speed of the train. Though that may sound surprising, I think it's true. Special relativity says more about this.
Special relativity "shows up" when the speeds get very high indeed.
I couldn't know for certain cause I don't know what course it is. But according to OSHA, a Exposure Control Plan is used for limited contact with bloody or body fluids so...
A:
is my guess
Answer:
The magnitude of displacement is 56.54 m
The direction of the displacement is along the line joining the two vectors.
Explanation:
The resultant displacement is always the line joining the initial and final position of the vectors.
As in figure,
the vector AB = 35 m
the vector BC = 15 m
the angle between AB and AC = 25' (minutes)
the resultant vector AC = ?
The resultant vector is given by the formula
AC² = AB² + BC² + 2 AB BC Cos θ
Substituting the values in the equations,
AC² = 35² + 15² + 2 x 35 x 15 x Cos 25'
= 56.54
Therefore, the magnitude of displacement is 56.54 m
The direction of the displacement is along the line joining the two vectors.
