Question

A navigational beacon in deep space broadcasts at a radio frequency of 50 MHz. A spaceship approaches the beacon with a relative velocity of 0.40c. What is the frequency of the beacon radio signal that is detected on the ship

Answer 1

Answer:

The frequency heard y the ship is 70 MHz.

Explanation:

True frequency, f = 50 MHz

speed of source, vs = 0

speed of observer, vo = 0.4 c

Let the frequency heard by the ship is f'.

Use the formula of doppler's effect

$f' = \frac{v +v_o}{v+ v_s}f\\\\f' = \frac{c + 0.4 c}{c}\times 50\\\\f' = 1.4\times 50\\​\\f' = 70 MHz$