Answer: v = (33320 - 340f2)/( f2 + 98)
Explanation: this question refers to Doppler effect, hence,
f1 = { V / (V - v)} x f2
f1 = 98Hz, f2 = 76 Hz, V = 340m/s, v = ?, fs = fsourcs
For f1,
98 = { 340 / (340 + v)} x fs ...(i)
for f2,
f2 = { 340 / (340 - v)} x fs ... (ii)
Divide (ii) by (i)
98/f2 = [{ 340 / (340 + v)} x fs]÷ [ 340 / (340 - v)} x fs]
98/f2 = {340 / (340 + v)} x fs x (340 - v)} / 340 x fs
98/f2 = (340 + v)/ (340 - v)
Cross multiplying
98(340 - v) = f2 (340 + v)
33320 - 98v = 340f2 + vf2
Collecting like terms
vf2 +98v = 33320 - 340f2
v(f2 +98) = 33320 - 340f2
v = (33320 - 340f2)/( f2 + 98)
