Answer:
average acceleration is 1.365 × m/s²
Explanation:
given data
initila speed u = -32.2 m/s
final speed v = 21.6 m/s
time taken t = 0.00394 s
solution
we get here average acceleration that will be express as
v = u + at ..........................1
put here value and we get
21.6 = -32.2 + a × 0.00394
solve it we get
a = 1.365 × m/s²
so average acceleration is 1.365 × m/s²
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.