N 2000, a 20-year-old astronaut left Earth to explore the galaxy; her spaceship travels at 2.5 x 10^8 m/s. She returns in 2040. About how old will she appear to be?

she'll be 42.3 years old

Explanation:

The year she left is 2020

she returns in 2040

the time observed to have passed by on earth is 40 years

she traveled at a speed of 2.5 x 10^8 m/s

From relativity, the astronaut will experience a time dilation and will age more slowly.

the time that is observed to pass on her ship will be gotten from

t' =

where t is the time that is observed to pass by an earthly observer

v is the speed of her ship

c is the speed of light = 3 x 10^8 m/s

v/c = 2.5/3 = 0.83  

t' = = 40 x 0.5578 = 22.3 years would have passed for her

This means that she'll be 20 + 22.3 = 42.3 years old

answer: d. a cme increases the amount of energy in the solar wind

explanation:

coronal mass ejections, also called cmes, are large clouds of plasma and magnetic field that erupt from the sun. only when the cloud is aimed at earth will the cme hit earth and therefore cause impacts. high-speed solar wind streams come from areas on the sun known as coronal holes.

emily ruth's annual premium is $1058.50

step-by-step explanation:

emily ruth is a female of 27 years age purchasing 20 year endowment insurance with face value $25000.

from the given table,

for females, the age of a male 3 years younger should be used.

so, we have to check for 24 year male for 20 year endowment.

it is 42.34 for every $1000 face value.

for a face value of $25000,

it is 25 * 42.34 = $1058.50

∴ emily ruth's annual premium is $1058.50