gas molecules have speeds comparable with those of rifle bullets, yet it is observed that a gas with a strong odor (ammonia, for instance) takes a few minutes to diffuse through a room why?
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A thin film of oil (n = 1.4) of thickness 1.4micrometers. is
compressed between two glass slabs (n = 1.5).
White light containing wavelengths from 400 to 700nm (measured in
air) is incident normally on the film.
In the reflected light, which wavelengths (from long to short)are
a) missing (4 of them) and b) enhanced (4 of them)
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In a rectangular coordinate system, a positive point charge q = 8.00 nC is placed at the point x = +0.150 m, y = 0, and an identical point charge is placed at x = -0.150 m, y = 0. Find the electric field at the following points.
a. Find the x and y components of the electric field at x = 0, y = 0.200 m.
Express your answers in newtons per coulomb separated by a comma.
b. Find the magnitude of the electric field at x = 0, y = 0.200 m.
Express your answer in newtons per coulomb.
c. Find the direction of the electric field at x = 0, y = 0.200 m.
Express your answer in degrees.
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Two divers jump from a 3-m platform. One jumps upward at 1.50m/s , and the second steps off the platform as the first passes it on the way down.
a) What is the first diver's speed as he hits the water?
b) What is the second diver's speed as he hits the water?
c) Which hits the water first?
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Does a magnetic dipole (in a permanent magnet) tend to align with the B-field or with the H-field?
The current loop (Amp
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A ship is using a chian to pull up its anchor in the ocean. The volume of the anchor is 2.4m^3, and the anchor is made of steel and has a density of 7800 kg/m^3. If the density of the ocean water is 1,000 kg/m^3, what is the change in weight on the anchor?
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A spherical conductor has a radius of 14.0 cm and a charge of 32.0 µC. Calculate the electric field and the electric potential at the following distances from the center.
a) r =8.0 cm
electric field: MN/C
electric potential: MV
b) r = 36.0 cm
electric field: MN/C
electric potential: MV
c) r = 14.0 cm
electric field: MN/C
electric potential: MV
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Most radioactive processes can only happen once for a given radioactive nucleus, changing the nucleus into another state (possibly a different radioactive state or even a different element) in the process. This means that for a given sample of radioactive material, the original radioactive substance is constantly being depleted. Since the rate of these decay events is directly proportional to the number of radioactive nuclei present, the decay is governed by the differential equation:
dN(t)/dt = -(lamda)N(t),
where N(t) is the number of nuclei of the original substance at time t, and the decay constant? ?, is positive because the amount of the substance is decreasing. The solution to this equation is an exponential, namely,
N(t) = No(e^(-lamda*t)) or N(t) = No(e^(t/Tao))
1. If the average count rate for a radioactive decay were 10 counts per minute, how long would you need to count to measure it to a precision of 5% of its value with 68% confidence (one standard deviation)?
2. The half-life of a decaying substance is the time it takes for 1/2 of that substance to disappear. Given an initial sample size of 1000 particles, how many particles are left after one half-life? Two?
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A) What is Electrical Resitivity (macroscopically)? Provide a
microscopic interpretation with a sketch
also:
B) What is an EMF? Explain:
C)What is Ohm's Law? Provide a graphical relationsip and interpretaions regarding current, voltage, and resistance:
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A 151 g oscillator has a speed of 130 cm/s when its displacement is 2.00 cm and 75.5 cm/s when its displacement is 5.10 cm . What is the oscillator's maximum speed?
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A spherical raindrop 2.1 mm in diameter falls through a vertical
distance of 3650 m. Take the cross-sectional area of a raindrop =
πr2, drag coefficient = 0.45, density of water to be 1000 kg/m3,
and density of air to be 1.2 kg/m3.
(a) Calculate the speed a spherical raindrop would achieve falling
from 3650 m in the absence of air drag.
(b) What would its speed be at the end of 3650 m when there is air
drag? (Note that the raindrop will reach terminal velocity after
falling about 30 m.)
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1 (a) A ball is launched from the ground toward a tall wall of a building at initial speed v0 = 21 m/s at an angle of 39 degrees relative to the horizontal. The wall is at a distance of 29 m from the launch point. What is the magnitude of the ball's velocity vector as it hits the wall?
Your answer should be in m/s, but enter only the numerical part in the answer box.
(b) A ball is launched from the ground toward a tall wall of a building at initial speed v0 = 27 m/s at an angle of 41 degrees relative to the horizontal. The wall is at a distance of 39 m from the launch point. What angle does the ball's velocity vector make with respect to horizontal as it hits the wall? [Note: a negative answer means the ball is moving on a downward angle. Be sure to enter the correct sign!]
Your answer should be in degrees, but enter only the numerical part in the answer box.
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A black hole has an event horizon radius of 3.00
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