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Physics Question Help?

1) A bat flying in a cave emits a sound and receives its echo 0.3 s later. How far away is the cave wall? Assume the speed of sound to be 340 m/s. Answer in units of m. 2) The velocity of the transverse waves produced by an earthquake is 4.44 km/s, while that of the longitudinal waves is 7.6368 km/s. A seismograph records the arrival of the transverse waves 74.3 s after that of the longitudinal waves. How far away was the earthquake? Answer in units of km. 3) The stoplights on a street are designed to keep traffic moving at 29 mi/h. The average length of a street block between traffic lights is about 80 m. What must be the time delay between green lights on successive blocks to keep the traffic moving continuously? There are 1.609 × 10^3m in a mile. Answer in units of s. Can anyone help me with these questions please, I have a test tomorrow and I'm confused on these three practice questions. Thank you guys! God bless <3

Public Comments

1. You shouldn't post so many at once 1. This is easy. So v=340 and t=.3 Since d=vt, de=340*.3=102m