I came across these questions in my homework (due a different day), and I have no idea what to do. If you could know which equation to use, or even help me step by step, that would be greatly appreciated! If you don't know how to do a problem, that's fine too.
1. Two trains on separate tracks move towards on another. Train 1 has a speed of 130 km/h, train 2 has a speed of 90 km/h. Train 2 blows its horn, emitting a frequency of 500 Hz. What is the frequency heard by the engineer on train 1?
2. A bat flying at 5 m/s emits a chirp at 40 kHz. If this sound pulse is reflected by a wall, what is the frequency of the echo, received by the bat?
3. An alert physics student stands beside the tracks as a train rolls slowly past. He notes that the frequency of the train whistle is 442 Hz when the train is approaching him and 441 Hz when the train is receding from him. Using these frequencies, he calculates the speed of the train. What value does he find?
4. Expectant parents are thrilled to hear their unborn baby's heartbeat, revealed by an ultrasonic motion detector. Suppose the featus's ventricular wall moves in cmiple harmonic motion with amplitude 1.8 mm and frequency 115 per minue. (a) Find the maximum linear speed of the heart wall. Suppose the motion detector in contact with the mother's abdomen produces sound at precisely 2 MHz, which travels through tissue at 1.5 km/s. (b) Find the maximum frequency at which sound arrives at the wall of the baby's heart. (c) Find the maximum frequency at which reflected sound is received by the motion detector.
5. A tuning fork vibrating at 512 HZ falls from rest and accelerates at 9.80 m/s. How far below the point of release is the tuning fork when waves of frequency 485 Hz reach the release point? Take the speed of sound in air to be 340 m/s.
6. A spersonic jet traveling at Mach 3 at an altitude of 20,000 m is directly overhead at time t=0. How long will it be before the ground observer encounters the shock wave? Where will the plain be when it is finally heart?
Thankyou again for the help!
1. Two trains on separate tracks move towards on another. Train 1 has a speed of 130 km/h, train 2 has a speed of 90 km/h. Train 2 blows its horn, emitting a frequency of 500 Hz. What is the frequency heard by the engineer on train 1?
2. A bat flying at 5 m/s emits a chirp at 40 kHz. If this sound pulse is reflected by a wall, what is the frequency of the echo, received by the bat?
3. An alert physics student stands beside the tracks as a train rolls slowly past. He notes that the frequency of the train whistle is 442 Hz when the train is approaching him and 441 Hz when the train is receding from him. Using these frequencies, he calculates the speed of the train. What value does he find?
4. Expectant parents are thrilled to hear their unborn baby's heartbeat, revealed by an ultrasonic motion detector. Suppose the featus's ventricular wall moves in cmiple harmonic motion with amplitude 1.8 mm and frequency 115 per minue. (a) Find the maximum linear speed of the heart wall. Suppose the motion detector in contact with the mother's abdomen produces sound at precisely 2 MHz, which travels through tissue at 1.5 km/s. (b) Find the maximum frequency at which sound arrives at the wall of the baby's heart. (c) Find the maximum frequency at which reflected sound is received by the motion detector.
5. A tuning fork vibrating at 512 HZ falls from rest and accelerates at 9.80 m/s. How far below the point of release is the tuning fork when waves of frequency 485 Hz reach the release point? Take the speed of sound in air to be 340 m/s.
6. A spersonic jet traveling at Mach 3 at an altitude of 20,000 m is directly overhead at time t=0. How long will it be before the ground observer encounters the shock wave? Where will the plain be when it is finally heart?
Thankyou again for the help!