1. The problem statement, all variables and given/known data A radar at rest emits microwaves at a frequency of 1.63 GHz onto a truck moving away from the radar. There is a frequency difference between the received and sent frequencies of 281 Hz. What is the velocity of the truck? 2. Relevant equations f(obs)=f(sent)*[(v+/-observer velocity)/(v+/-source velocity)] 3. The attempt at a solution (1.63e9 Hz + 281 Hz) = (1.63e9 Hz)*((343 m/s - X)/(343 - 0)) (((1.63e9 Hz + 281 Hz)*343) / 1.63e9 Hz) - 343 m/s = X X=5.91e-5 m/s but because that answer was ridiculous, I redid the question with 3e8 m/s as my V), which gave X=49.88 m/s, but that was wrong too.