Imagine that you place your stereo speakers outside (to provide music for a party). They are places distance of 1.5 m apart along a line we will call the y axis. Imagine that both speakers are reproducing the sound of a female singer holding a solo high A (880 Hz) for several seconds consider a line parallel to the y axis but 8.0 m from it. At what points along this second line would the sound be loudest? At what points would it be weakest?
In: Physics
Is the atmosphere of a planet orbiting a hot F star likely to absorb or reflect more incoming radiation from its star than an M star? Why? What about the surface (assuming some part of both planets contains ice cover)? Why?
In: Physics
A) A runner begins to run from rest and it takes him 10.4 meters to speed up to a speed of 12m/s. What is this runner's acceleration?
B) What is the final speed of an object dropped from rest at a height of 120m?
C) What would the final speed of a mass sliding through a 32m frictionless incline of 24 degrees be?
D) What is the range of a projectile shot horizontally at a height of 46m with a speed of 15m/s?
E) For the initial velocity vector v>=10x^+8y^, find a) the direction angle, b) the speed c) the range if this is the initial speed vector for a projectile with a full parabolic trajectory.
In: Physics
An arrow is shot straight up from a horizontal level with an initial velocity of 45j m/s.
A. Find its flight time.
B. Find its position at t=6.0s
C. What is its velocity at t=6.0s
D. Graph v(t) vs. t.
In: Physics
Consider a shallow-water wave of length 1.5km propagating in an ocean that is 62.5m deep.
a) Calculate the wave’s speed C and period T. (3P)
b) Now suppose that this wave propagates into a region in which there is a current of strength U that opposes the wave propagation. Explain how this modifies the dispersion relation and the wave speed. (2P)
c) Assuming that the wave’s frequency ω remains constant, create
a plot of the wavelength λ as a function of the current speed U. As
U increases, what do you expect to happen to
i) the wave’s length?
ii) the wave’s amplitude?
iii) the wave’s steepness? (5P)
d) Still assuming that ω remains constant, what happens as the speed of the current U approaches the phase speed C that you calculated in part a? Is this physical? What behavior would you expect to see in real, nonlinear waves if they encountered such a current? (3P)
In: Physics
A 1000. kg remote-controlled stunt car traveling at 17.0 m/s north collides with a 900. kg remote-controlled stunt car traveling at 18.0 m/s east. What is the speed of the entangled cars immediately after the collision? 7.2 m/s 7.7 m/s 10.2 m/s 12.4 m/s
In: Physics
If you length a bar magnet describe the affect in the shape of its magnetic field?
In: Physics
State v. Stewart
Did she shoot him dead in self-defense?
In: Physics
1. Calculate the filling factor of a photovoltaic cell
whose dimensions are 15 cm per side, and a thickness of 200 µm of
which 99% correspond to the “p” type absorbent layer and where
there is also a amount of 13500 electrons. The thickness of the
space loading region junction is 200 nm.
The cell is subjected to standard test conditions, which produces
every second a generation of electron-hollow pairs of 2.0x10¹⁹ cm⁻³
and which translates into an increase in its density of 4.0x10¹³
cm⁻³. The efficiency of the cell is measured at 20%.
Consider that the cell is in thermal equilibrium (300K), its
prohibited band is 1.12 eV and that the mobility coefficients are
1360 cm² / Vs for electrons and 450 cm² / Vs for holes.
In: Physics
1)Describe TWO differences between viscous and inviscid flows in Balance Law of Linear Momentum.
In: Physics
In: Physics
Question 5. The 2.50 µc point charges are located on the x-axis. One is at x = 1.00 m, and the other is at x = -1.00 m. Determine the electric field on the y-axis at y = 0.500 m. Answer in Newtons per Coulombs.
Question 6. The 2.50 µc point charges are located on the x-axis. One is at x = 1.00 m, and the other is at x = -1.00 m. Calculate the electric force on a -3.50 µc placed on the y-axis at y=0.500 m. Answer in newtons.
In: Physics
Can the Hubble Space Telescope (2.4 m diameter) or the
largest optical telescope on Earth
(the Keck Telescope in Hawaii with 10 m diameter) observe manmade
items left on the moon
(e.g. the flag ~ 1.25 m long and lunar rover ~ 3 m long)? Show your
work. If not, calculate the
smallest size each telescope can resolve on the Moon and the
minimum telescope aperture
size required to resolve these objects.
In: Physics
If the Sun were to become a black hole but maintain all of its mass, what would be its Schwarzschild radius? Given this and the fact that Earth’s average distance from the Sun is about 150 million km, would the gravity of the black hole pull Earth into it? Why or why not?
In: Physics
As part of an interview for a summer job with the Coast Guard, you have been asked to help determine the search area for two sunken ships by calculating their velocity just after an accident. According to the last radio transmission from the luxury liner Apollo (3.9 × 104 metric tons), it was going due east at a steady speed of 21 knots in calm seas through a rare fog just before it was struck broadside by the freighter Blake (6.1 × 104 metric tons), which was traveling north at steady speed of 11 knots. The transmission also noted that when the freighter's bow pierced the hull of the liner, the two ships stuck together and sank. What was the speed and direction of the ships after the collision ? (Take zero degrees to be straight east and counter-clockwise as positive.)
1)____ knots
2)____ degrees
In: Physics