Briefly explain the two postulates of relativity, how they differed from classical physics, and

why Einstein was led to propose them. List at least 2 implications of the postulates.

How to find the central pressure of Jupiter? Assuming we know the mass of the Jupiter.

What is light? You can start by describing the different historic models for light and explain their individual strength and shortcomings in explaining observable phenomena. Then, try to summarize our current quantum mechanic understanding and highlight its implications for all matter and energy. Finally, consider identifying visible light within the electromagnetic (EM) spectrum and discuss applications that may depend on different light effects such as photoelectric or electro-luminescent effect.

Problem 1 Two friends are planning to go on a 480 mile-long bike ride over the summer. One is planning to ride a mountain bike with 26-in. tires, the other has a touring bike with 27-in. tires. a) How many more revolutions will the mountain bike tires make in that distance than the touring bike? b) Typical gearing for moste bicycles ranges from 30 to 50 teeth on the chain wheel (front gears) and 12 to 30 teeth on the rear cog. How many more revolutions on the pedals will the mountain biker make during the trip. Assume he is pedaling 85% of the time and has a 42-tooth chain wheel and a 21-tooth rear cog. c) If both cyclists have 170-mm cranks on their bikes, what will be the mechanical advantage (consider only the movement of the feet with a constant force for walking and riding), in percent, that each rider will have achieved over walking the same distance.

Density of modes. The essentials of calculating the number of modes of vibration of waves confined to a cavity may be understood by considering a one-dimensional example. (a) Calculate the number of modes (standing waves of different wavelength) with wavelengths between 2.0 cm and 2.1 cm that can exist on a string with fixed ends that is 2 m long.

(b) Calculate, in analogy to our three

dimensional calculation, the number of modes per unit wavelength per unit length, .

(c) Show that in general the number of modes per unit wavelength per unit length for a string of length L is given

^{Wi-Fi RF Linearization} can you explain this topic in a simple way to make me understand it ?

Materials Science: Composites (Chapter 16)

How do we predict the stiffness and strength of the various types of composites?

Include an original free body diagram and an original extended free body diagram representing the ideal disposition of the four main forces acting on an aeroplane during the five different stages of flight. Explain your diagrams and describe the effect of each of these forces in the aeroplane translation and rotation. Include the angle of attack.

The emission wavelength lies between 275 nm and 450 nm and the light yield per neutron is reported to be 20000 photons/MeV neutron energy

(a) What largest work function of a material used for a photo cathode would be acceptable that still allows detection of an emission originating from the scintillator?

(b) What is the maximum kinetic energy of electrons emitted from the photo cathode, given the emission wavelength range of the scintillator?

(c) How much charge is being generated per single neutron, assuming a 3 MeV neutron and a photon-to-electron conversion efficiency (quantum efficiency) of 15%? Would this charge be detectable if you use an Electrometer2 that has a resolution limit of 10 fC?

Ernest Rutherford (the first New Zealander to be awarded the Nobel Prize in Chemistry) demonstrated that nuclei were very small and dense by scattering helium-4 nuclei (⁴He) from gold-197 nuclei (¹⁹⁷Au). The energy of the incoming helium nucleus was 7.97 ✕ 10⁻¹³ J, and the masses of the helium and gold nuclei were 6.68 ✕ 10⁻²⁷ kg and 3.29 ✕ 10⁻²⁵ kg, respectively (note that their mass ratio is 4 to 197). (Assume that the helium nucleus travels in the +x direction before the collision.)

A)If a helium nucleus scatters to an angle of 116° during an elastic collision with a gold nucleus, calculate the helium nucleus' final speed (in m/s) and the final velocity (magnitude in m/s and direction counterclockwise from the +x-axis) of the gold nucleus. b) What is the final kinetic energy (in J) of the helium nucleus?

A heat engine made with an ideal gas with f = 5 degrees of freedom has 3 steps. Starting with a volume of 8 liters and a pressure of 1.3 × 10^5 Pa, the gas is compressed adiabatically to a volume of 1 liter and a pressure P2. Next the gas expands at constant pressure back to 8 liters, then the pressure drops at constant volume back to 1.3×10^5 Pa. Draw the cycle in a P −V diagram. Calculate the pressure P2. Calculate the efficiency of the engine. Calculate the ratio Tmin/Tmax of minimum and maximum temperatures during the cycle and compare the efficiency of this engine to eCarnot of a Carnot engine operating with the same value of Tmin/Tmax.

if a rocket was orbiting a planet and then the mass of the planet suddenly decreased what would happen to the movement of the rocket?