As you stand near a railroad track, a train passes by at a speed of 34.5 m/s while sounding its horn at a frequency of 215 hz. what frequency do you hear as the train approaches you and what frequency while it recedes? take the speed of sound in air to be 341 m/s.

Imagine you work as a consultant, and your daily job involves listening to the constructive criticism of others. as part of your job, you must listen to opposing viewpoints to make important decisions. in this activity, you are a consulting dam engineer. you must make a decision about four different dams; should they be repaired, taken down, or left alone? you will listen to contrasting opinions about what should be done with the dams before you make the final decision. as the consulting dam engineer, what do you decide to do with this dam? explain your reasoning. by making your decision, did you support the opinions of the mayor and/or the dam safety official? why or why not? (site 1)

In a system, when potential energy decreases, then entropy also decreases. true false

What is the primary force that suspension bridges use cables to hold their spans up? a. tension force b. resistance force c. normal force d. elastic force e. applied force