Theory Of Rlelativity

1) Annual energy consumption in the United States (Q24; Giancoli Chap 26)

The total annual energy consumption in the United States is about 8 10 J. фЂЃµ 19 How much mass would have to be

converted to energy to fuel this need?

2) The nearest star to Earth (Q49; Giancoli Chap 26)

The nearest star to Earth is Proxima Centauri, 4.3 light-years away. (a) At what constant velocity must a

spacecraft travel from Earth if it is to reach the star in 4.0 years, as measured by travellers on the spacecraft? (b)

How long does the trip take according to Earth observers?

3) Electron in a uniform magnetic field (Q54; Giancoli Chap 26)

An electron ( . kg) 31 9 11 10m фЂЂ фЂЃµ фЂЂÑ' enters a uniform magnetic field B фЂЂ 1.8 T,

and moves perpendicular to the

field lines with a speed v фЂЂ 0.92c. What is the radius of curvature of its path? See hint for Problem 42.

4) Producing an electron and a positron (Q53; Giancoli Chap 26)

What minimum amount of electromagnetic energy is needed to produce an electron and a positron together? A

positron is a particle with the same rest mass as an electron, but has the opposite charge. (Note that electric

charge is conserved in this process. See Section 27вЂ"6.)

5) Running a 100-W light bulb on matter (Q52; Giancoli Chap 26)

How many grams of matter