Download SES4U Distance Calculation Practice 1 light year = 9.46 x 1015

SES4U
Distance Calculation Practice
1 light year = 9.46 x 1015 meters
1 Astronomical Unit = 150 000 000 000 meters
Kilometer = 1 000 meters
Speed of light = 300 000 000 m / s
Use the preceding values to solve the following questions using unit conversion like the example below.
Example: Wolf-359 is located in the Leo constellation and is 7.78 ly from the Sun. How many AU does
this represent?
1 AU
150 000 000 000 meters
X
9.46 x 1015 meters
1 ly
X
7.78 ly
=
490 658.67 Astronomical Units
1. How many AUs are one light year? (ANS: 63 066.67 AU)
2. If the circumference of the Earth is 40 075 km, how many times around the Earth would it take
to go from the Sun to the asteroid belt if the asteroid belt is 2.7 AU from the Sun? (ANS:
10106.05 times around the Earth)
3. The Crab nebula is a supernova remnant in the constellation Taurus. The Crab Nebula is
52,032,906,226,837 km in diameter. What is the diameter of the Crab nebula in AU? in light
years?(ANS: 353 552.7 AU; 5.6 ly)
4. The Oort Cloud is roughly 50 000 AU from the Sun. If the Oort cloud is a sphere, what is the
diameter of the Oort cloud in light years? (ANS: 1.59 ly)
5. Neptune is 4,487,936,120.73 km away from the Sun. What is this distance in AU? (ANS: 30 AU)
6. The largest moon of Saturn, Titan, is Saturn's only moon to have a dense atmosphere. If Titan's
semi major axis is 1,221,870 km, how long would it take light to travel from titan to Saturn's
surface? (ANS: 4 seconds)
7. Kepler 10-b, an earth-like planet candidate, is 35,683,811.48045 AU away from our star system.
a. What is this distance in light years? (ANS: 565.81 ly)
b. How fast would a shuttle need to travel to make this journey in 1 lifetime (1 lifetime =
75 years), in m/s? (ANS: 2.26 x 10 9 m/s)
c. Is this speed possible? Explain your answer.
8. The shortest distance from Earth to Mars is 54,500,000 km.
a. How long would it take a shuttle travelling at 250,000 km/h to reach Mars in hours? in
earth days?(ANS: 218 hours; 9 earth days)
b. How long would it take for a signal travelling at the speed of light to reach Mars at its
shortest distance to Earth? (ANS: 181.67 seconds)
c. The maximum distance between Earth and Mars is 401 million km. How long would it
take a signal travelling at the speed of light to travel this distance? (ANS: 1336.67
seconds)
9. If Earth existed in another star system, where Earth was named Erthos, was 420 000 000 km
from its star and orbited around that star in 770 days, what would the value of an AU be? What
would the value of a light year be? (ANS: 1 ly = 2x1016 m)
10. If light from early Earth ( 4.5 billion years) radiated outwards into space, how far would a star
system that is now seeing the light be from Earth? (4.257 x 1025 m)