A hydrogen line in a star's spectrum has a frequency of 6.17x10^14 Hz
when stationary. In Rigel's spectrum,
it is shifted downward by 4.26x10^10
Hz. What is Rigel's velocity relative
to us?
PLS HELP!

V = 299,958589.8 m/s

Explanation: To calculate Rigel velocity relative to us, we should use doppler effect formula.

Fo = (c + Vo) f/ ( c - Vs)

Fo/f = (c + Vo) / ( c - Vs)

If Vo = Vs = V approximately

4.26 × 10^10 = (3×10^8 + V) 6.17×10^14/(3×10^8 - V)

4.26×10^10/6.17×10^14 = (3×10^8 + V)/(3×10^8 - V)

6.9×10^-5 = (3×10^8 + V)/(3×10^8 - V)

Cross multiply

20713.13 - 6.9×10^-5V = 3×10^8 + V

Collect the like terms

6.9×10^-5V + V = 3×10^8 - 20713.13

1.000069V = 299979286.9

V = 299979286.9/1.000069

V = 299,958589.8 m/s

Therefore, Rigel's velocity relative to us is 299,958589.8 m/s

b.

explanation:

10.0

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.