1. During the Apollo missions, astronauts traveled from the Earth to the Moon and back. When they were close to Earth, gravity accelerated them toward Earth, but when they were close to the Moon, gravity accelerated them toward the Moon. However, there is a point somewhere between the Earth and the Moon where they experienced no acceleration due to gravity.

   The Earth is 6.0×1024 kg, the Moon is 7.3×1022 kg in mass, and the two are 3.8×108 m apart. How far from Earth were the astronauts when they experienced zero acceleration due to gravity? Hint: remember that zero acceleration requires zero net force.

A sound wave with an intensity level of 80.6 dB is incident on an eardrum of area 0.600 ✕ 10^-4 m². How much energy is absorbed by the eardrum in 4.0 minutes?
µJ?

A source of sound waves of frequency 1.2 kHz is traveling through the air at 0.55 times the speed of sound.

(a) Find the frequency of the sound received by a stationary observer if the source moves toward her.
Hz
(b) Repeat if the source moves away from her instead.
Hz

4.     Explain how following measurements are made. Please mention equipment used during those measures.

a.      Air quality

b.     Wind speed

c.      Carbon Monoxide

d.     Sound level

e.      Personal noise exposure

f.      Vibration

A long solenoid with 1.65 103 turns per meter and radius 2.00 cm carries an oscillating current I = 6.00 sin 120πt, where I is in amperes and t is in seconds. (a) What is the electric field induced at a radius r = 1.00 cm from the axis of the solenoid? (Use the following as necessary: t. Let E be measured in millivolts/meter and t be measured in seconds.) E =

(b) What is the direction of this electric field when the current is increasing counterclockwise in the solenoid?

clockwise counterclockwise

Correct: Your answer is correct.

A uniform disk of mass M is rotating freely about its center On its rim lie a cockroach of mass M/3 Initially the cockroach and disk rotate together with an angular velocity of 2.5 rad/s Then the cockroach walks halfway to the center of the disk. What is the new angular velocity of the system?

A 425-m long spaceship passes by an observer at the speed of 2.60×108 m/s. What length does the observer measure for the spaceship? .... m

What is the rest energy of 37 g of shelled peanuts? .... J

Find the energy in joules of a single photon of microwave radiation with the wavelength of 0.76 cm..... J

Using the Bohr model, find the wavelength in nanometers of the radiation emitted by a hydrogen atom, when it makes a transition from the n = 6 state to the n = 4 state. ..... nm

Iodine-131, a radioactive isotope, has a nuclear mass of 130.8770 u. The atomic number of iodine is 53. Find the binding energy of the I-131 nucleus in joules.

37) A pendulum whose period in a vacuum is 2.3 second is placed in a resistive medium. Its amplitude on each swing is observed to be half that on the previous swing. What is its new period? Given that the pendulum bob is of mass 0.2 kg, and is subjected to a periodic force of amplitude 0.5 N and period 1 s, find the angular amplitude of the resulting forced oscillation.

Consider and airplane flying at a pressure altitude of 40,000 feet and a density altitude of 30,000 feet. Calculate the outside air temperature.

Design an experiment to find the relationship between the mass on the spring and the period of oscillation. Include: What quantity will you vary?

Which quantities will you hold constant?

What quantities will you measure?

What will you plot?

A hollow, plastic sphere is held below the surface of a freshwater lake by a cord anchored to the bottom of the lake. The sphere has a volume of 0.640 m3 and the tension in the cord is 2120 N.

a) Draw a free body diagram when sphere is at the bottom.

b) The cord breaks and the sphere rise to the surface. When the sphere comes to rest, what fraction of its volume will be submerged?

What is an “X ray” (radiograph)—what creates the image?

What sort of radiation is involved? Are X rays “perfectly safe”? If not, what are the dangers?

A horizontal piston assembly contains water. The piston is connected to a shaft, which can apply different forces to the piston as the water is expanded or compressed. Initially the apparatus contains a saturated liquid-vapor mixture of water at .9 bar with quality of 80% and a volume of 1.0 m^3. The shaft is programmed to move following a polytropic processs until the volume doubles and the pressure is 0.7 bar.

A) For the initial state, what percent of the total volume is occupied by vapor?

B) Could Kinetic and potential effects be neglected for the system? Why or Why not?

C) Determine the amount of heat transfer required to accompany the process in kJ

D) For the initial state, calculate the amount of mass present in the vapor phase kg

E) Determine the type of polytrophic process (find n when PV^n= Constant

If you could answer all the question you’d be absolutely amazing

Consider a system of three particles with three energy eigenstates of 0, 3ε and 5ε. Write the partition function for three particle system.
a) If the particles are non-identical
b) If the particles are obeying Bose-Einstein statistics.
c) If the particles are obeying Fermi-Dirac statistics

2.) For this problem the heights are low enough that the acceleration due to gravity can be approximated as -g. (Note: even at low Earth orbit, such as the location of the International Space Station, the acceleration due to gravity is not much smaller then g. The apparent weightlessness is due to the space station and its occupants being in free-fall.)

A rocket is launched vertically from a launchpad on the surface of the Earth. The net acceleration (provided by the engines and gravity) is a₁ (known) and the burn lasts for t₁ seconds (known). Ignoring air resistance calculate:

a) The speed of the rocket at the end of the burn cycle.

b) The height of the rocket when the burn stops.

The main (now empty) fuel tank detaches from the rocket. The rocket is still propelled with the same acceleration as before due to the secondary fuel tank.

c) Calculate how long it takes for the main tank to fall back to the ocean back on the surface of the Earth in order to be recovered for next use.

d) Calculate the height of the rocket at the time when the tank hits the ocean.

e) At the time the main tank hits the ocean the secondary fuel tank runs out of fuel. Calculate the maximum height above the surface of the Earth that is reached by the rocket.