alleryStart learning →An astronaut on the moon receives a radio signal from Earth that takes 1.28 s to arrive. Using c = 3.00 x 10^8 m/s, what is the distance from Earth to the moon?
A2.34 x 10^5 km
B3.84 x 10^5 km
C3.84 x 10^8 km
D4.27 x 10^8 km
Answer & Solution
Correct answer: B. 3.84 x 10^5 km
1. Distance equals speed multiplied by time, d = v multiplied by t.
2. Substitute v = 3.00 x 10^8 m/s and t = 1.28 s.
3. Multiplying gives d = 3.84 x 10^8 m, which is 3.84 x 10^5 km.
4. 3.84 x 10^8 km shifts the decimal point three places too far, and 2.34 x 10^5 km does not match this multiplication.
5. 4.27 x 10^8 km does not come from this calculation at all.
6. So 3.84 x 10^5 km is correct.
_Source: OpenStax Physics (CC BY 4.0), Ch 10 "Special Relativity", section 10.1 Postulates of Special Relativity_
Keep practising Special Relativity
Browse all Special Relativity questions for Alberta Diploma Exams, or explore more Physics topics.
Related questions
Knock out the false light claimsIn the RHIC collider, gold ions are accelerated to about 99.7 percent of the speed of lighDeuterium has a binding energy of 3.56 x 10^-13 J. Using c = 3.00 x 10^8 m/s, what is its The nucleus of fluorine-18 has a mass defect of 2.44 x 10^-28 kg. Using c = 3.00 x 10^8 m/What is the rest energy, E0, of an object with a mass of 1.00 g? Use c = 3.00 x 10^8 m/s.A rod has a proper length of 100 m. An observer moving relative to the rod at 0.80c measurA spaceship has a proper length of 50 m. As it flies past Earth at 0.95c, what length woulHow has time dilation been experimentally confirmed?