Imagine that at some point during the Ice Age a boulder with a mass of 380kg rolls off a cliff and onto a smooth (approximately frictionless) glacier so that just before it hits the glacier its
̂
velocity is ??? = (68m/s)î + (52m/s)k where the z-axis is the
positive vertical direction
(perpendicular to the surface of the earth) and the x-axis is parallel to the surface of the earth.
̂1. (a) (4 points) What is this boulder’s initial momentum (just before it hits the glacier) in î, ĵ, k
notation?
̂
(b) (6 points) What is its momentum just after it hits the glacier
in î, ĵ, k notation? How do you
know (think about and discuss force directions and conservation of momentum in component form)?
In: Physics
Which one has a larger final entropy, reversible isothermal process or reversible adiabatic process when expanding to the same final volume for an ideal gas?
What do you assume the entropy S for a perfect crystal when T = 0?
Is the S(0) still zero if the crystal is not perfect? Why?
How to calculate dS when under the constant pressure and cp is given?
How to calculate the entropy of H2O at 500 K?
How to calculate the entropy change for a chemical reaction if you can find the S for each chemical?
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Spectrometer Lab
Summarize this experiment from purpose to procedure to analysis.
Include all important theoretical equations.
{¶ ≤ 100 words}
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Body A in the figure weighs 97 N, and body B weighs 80 N. The coefficients of friction between A and the incline are μs = 0.57 and μk = 0.23. Angle θ is 28°. Let the positive direction of an x axis be up the incline. What is the acceleration of A if A is initially (a) at rest, (b) moving up the incline, and (c) moving down the incline?
In: Physics
In our review of fluids this week, particularly of fluids in motion, we have come across 3 important rules that govern that motion: the continuity equation, Bernoulli's principle, and Poiseuille's principle.
Please give an example for each one. Also, can you find/see the importance of these rules, fluid motion in general, in your field of study?
Please no handwritten or picture responses - only typed replies
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5. (5)
(a) Describe the de Broglie Model (also known as the de Broglie-Bohr Model) of the hydrogen atom.
(b) What was its motivation? (To address what problem was it proposed?)
(c) What drawbacks did it still have when it was proposed?
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A motor with an internal resistance of R(motor) = 50 Ohms
requires a potential difference of V(motor)=20V to work properly.
As you don't have a 20V power source, you place two 12V batteries
in series with a custom-built resistor with resistance R1.
(a) How much current moves through the motor when it is working
properly?
(b) What must be the resistance of your custom-built resistor so
that the potential difference across the motor is 20V?
(c) If you built your resistor from aluminium wire with diameter of
0.03mm and a resisticity of 2.65*10^-8 Ohmes meter, what length of
wire must you use to create the necessary resistance of R1?
(d) What is the ratio of the power used by the motor to the power
dissipated by the resistor, P(motor)/P(R1)?
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What force, applied tangentially to the Earth along 45° of latitude in the direction of rotation for 1 day would result in a new day length that is shorter by 5.2 seconds? The Earth has mass 5.98x1024kg and radius 6380 km. Answer:
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A 3 kg object is moving along the +y+y direction with a speed of 4 m/s when it experiences an impulse of 5i^−8j^5i^−8j^ Ns. What is the object's speed after the impulse is applied?
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list at least two weaknesses of using sound to image an object. can these weaknesses be overcome, how?
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0-9. GREENHOUSE EFFECT
CO2 passes short wave length light (visible) but blocks long wave
length
radiation (IR). Explain how adding CO2 to an atmosphere increases
the
surface temperature of a planet. Consider the temperature of the
sources
of radiation in and out.
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Show that angular momentum is conserved for a force law F = kr and find the allowed orbits.
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When light with a wavelength of 215 nm is incident on a certain metal surface, electrons are ejected with a maximum kinetic energy of 3.33 × 10 − 19 J. Determine the wavelength of light that should be used to quadruple the maximum kinetic energy of the electrons ejected from this surface.
In: Physics
Consider the three basic quantities of a circuit: voltage (potential difference), current, and resistance.
In general terms, describe each one in your own words and its basic characteristic/property, and can you do an analogy of these quantities with a fluid system, say a stream of water?
Further, since many of you are in the medical field, can you relate a basic circuit and its components to a system of the body, maybe the circulatory system? If, what is the analogy between the basic circuit components to components of the circulatory system?
Please no handwritten or picture respones - only typed replies
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Compare and contrast the photon nature of light with the wave nature of light, making sure to address the following properties:
a: color
b: intensity
C: energy
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