Question

How long would it take a message sent as radio waves from earth to reach mars?

Answer 1

`longest \: dstance \: btw \: earh - mars \\ (150 + 230) * {10}^(6) km \\ t = (d)/(c) \\where \: c \: is \: the \: speed \: of \: light \\ = \frac{380 * {10}^(6) km}{3 * { {10}^(5) }km. {sec}^( - 1) } \\ \\ when \: mars \: is \: close \: to \: earth \\ ( 230 - 150) * {10}^(6) km \\ t = (d)/(c) \\where \: c \: is \: the \: speed \: of \: light \\ = \frac{80 * {10}^(6) km}{3 * { {10}^(5) }km. {sec}^( - 1) }`