1. The problem statement, all variables and given/known data A radio station transmits a radio wave of 100Mhz. The radio wave is detected by a receiver via two diffrent paths , a direct path and refelcted path form a wall. The distance travelled by the radio wave for a direct path and refelcted path is 1500m and 1512 m respectively. Explain whether the intefrenece is constructive od destructive? 2. Relevant equations 3. The attempt at a solution refer to the sample ans attcahed, i don't undertstand why there's a phase change of 1/2 lambda when the wave is reflected?