Your teacher walks outside the classroom to have a conversation with the principal. unknown to the teacher, while she is outside the room, the sound waves are transmitted around the edge of the door and spread out on the other side and you can hear the conversation. this is due to sound wave
a) absorption.
b) diffraction.
c) interference.
d) reflection

You are a sales representative for a company that makes a new alternate fuel for vehicles. you have prepared a presentation for the environmental engineers to sell your new product. what question do you expect the audience to ask regarding whether the new fuel will cause less damage to the environment? a. do we have to change any parts of the vehicle to use this alternate fuel? b. will the vehicles get better fuel mileage with the alternate fuel? c. how much greenhouse gas does your fuel produce compared with current fuel sources? d. is the alternate fuel more expensive than fossil fuel?