Exam 26: Special Relativity

Three spaceships A,B,and C are in motion as shown in the figure.The commander on ship B observes ship C approaching with a relative velocity of 0.82c.The commander also observes ship A,advancing in the rear,with a relative velocity of 0.50c.What is the speed of ship C as measured by the captain of ship A?

The total energy of a moving electron is $0.758 \mathrm { MeV }$ What is the speed of the electron in terms of c? The rest mass energy of an electron is 0.511 MeV.

A 1.0-kg aluminum ingot is heated from 0°C to 100°C.By what amount does its mass change? The specific heat of aluminum is 900 J/kg ∙ K.(c = 3.0 × 10⁸ m/s)

A stretch of land is 12.5 km long on a map. (a)What would be its length to an observer moving by,parallel to the stretch,at $0.9500 c ?$ (b)Which is the proper length for this stretch of land? (c)How fast relative to Earth would the observer have to move for the land to appear 6.50 km long? Express your answer in terms of the speed of light.