Rapid variability in quasars indicates that the region in which the energy is generated must be small. you can show why this is true. suppose, for example, that the region in which the energy is generated is a transparent sphere 1 light-year in diameter. suppose that in 1 s this region brightens by a factor of 10 and remains bright for two years, after which it returns to its original luminosity. draw its light curve (a graph of its brightness over time) as viewed from earth.

real, smaller and upside-down.   so the answer should be b.

no simpler subs form complex ones. synthesise = make

jupiter is the largest planet in our solar system, having a mass and radius that are respectively, 318 and 11.2 times that of earth. suppose that an object falls from rest near the surface of each planet and that the acceleration due to gravity remains constant during the fall. each object falls the same distance before striking the ground. determine the ratio of the time of fall on jupiter to that on earth.

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s