Questions from Modern Physics

Q: The siren of a fire engine that is driving northward at 30

The siren of a fire engine that is driving northward at 30.0 m/s emits a sound of frequency 2000 Hz. A truck in front of this fire engine is moving northward at 20.0 m/s. (a). What is the frequency o...

Q: A stationary police car emits a sound of frequency 1200 Hz that

A stationary police car emits a sound of frequency 1200 Hz that bounces off a car on the highway and returns with a frequency of 1250 Hz. The police car is right next to the highway, so the moving car...

Q: An aluminum tea kettle with mass 1.10 kg and containing

An aluminum tea kettle with mass 1.10 kg and containing 1.80 kg of water is placed on a stove. If no heat is lost to the surroundings, how much heat must be added to raise the temperature from 20.0°C...

Q: A jet plane flies overhead at Mach 1.70 and at

A jet plane flies overhead at Mach 1.70 and at a constant altitude of 1250 m. (a). What is the angle a of the shock-wave cone? (b). How much time after the plane passes directly overhead do you hear...

Q: The shock-wave cone created by a space shuttle at one

The shock-wave cone created by a space shuttle at one instant during its reentry into the atmosphere makes an angle of 58.0 with its direction of motion. The speed of sound at this altitude is 331 m/...

Q: In an effort to stay awake for an all-night study

In an effort to stay awake for an all-night study session, a student makes a cup of coffee by first placing a 200-W electric immersion heater in 0.320 kg of water. (a). How much heat must be added to...

Q: (a). In a liquid with density 1300 kg/m3

(a). In a liquid with density 1300 kg/m3, longitudinal waves with frequency 400 Hz are found to have wavelength 8.00 m. Calculate the bulk modulus of the liquid. (b). A metal bar with a length of 1.5...

Q: While running, a 70-kg student generates thermal energy at

While running, a 70-kg student generates thermal energy at a rate of 1200 W. For the runner to maintain a constant body temperature of 37C, this energy must be removed by perspiration or other mecha...

Q: In very cold weather a significant mechanism for heat loss by the

In very cold weather a significant mechanism for heat loss by the human body is energy expended in warming the air taken into the lungs with each breath. (a). On a cold winter day when the temperatur...

Q: You are given a sample of metal and asked to determine its

You are given a sample of metal and asked to determine its specific heat. You weigh the sample and find that its weight is 28.4 N. You carefully add 1.25 × 104 J of heat energy to the sample and find...