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.
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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
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Wi-Fi RF Linearization can you explain this topic in a simple way to make me understand it ?
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Materials Science: Composites (Chapter 16)
How do we predict the stiffness and strength of the various types of composites?
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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.
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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?
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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?
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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.
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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?
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A computer disk drive is turned on starting from rest and has constant angular acceleration.
Part A
If it took 0.420 s for the drive to make its second complete revolution, how long did it take to make the first complete revolution?
Part B
What is its angular acceleration, in rad/s2?
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Explain the differences between primary electrons, secondary electrons, Auger electrons, and backscattered electrons and how they are used in SEM imaging and analysis
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47. a) Imagine that you are conducting an activity
with a laser to create an interference
pattern. Use the appropriate equations to predict two
ways (other than the way
described in the following example) to change the
interference pattern in order to
have closer fringes. Explain your predictions.
Here’s an example to get you started:
According to the equation
Δx = Lλ/d ,
the distance between the fringes (∆x) is proportional
to the wavelength (since
they are both numerators). This means that increasing
one will increase the other.
Therefore, decreasing the wavelength will decrease the
distance between the fringes.
(Hint: You can use the “Thomas Young’s Double-slit
Experiment” simulation from
this lesson to verify your
predictions.)
b) If you were using a hands-on activity to verify
your predictions and use
measurements to determine the wavelength of the laser
being used, describe any
safety precautions you would take and sources of error
that you might encounter. Be
sure to explain how you might reduce the effects of
the sources of error.
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