The average intensity of a particular TV station
In: Physics
Which of the following statements are true?
True False Magnetic field lines always start at a North
and end at a South pole.
True False When placing a dipole magnet into a magnetic
field, it will be accelerated perpendicular to the field
lines.
True False The force on a moving charge is perpendicular
to both the field and its velocity.
True False The larger the charge of a moving particle,
the more it will accelerate inside of a magnetic field.
In: Physics
Which process, conduction, convection, or radiation is most involved with the distribution of heat around the earth?
In: Physics
Write about czochralski method (melt) in half of a sheet
In: Physics
Ionization chambers, proportional counters and Gieger-Muller counters are all gas-filled radiation detectors. Sketch a graph of the signal (pulse of charge collected) as a function of the voltage applied. Describe what happens to the number of ion pairs collected as a function of Applied Voltage, (from very low voltage to high voltage). In particular indicate the regions of this graph which define the three different detector types.
In: Physics
(a) Find the photon energy and wavelength for the series limit
(shortest wavelength) in the Balmer series (nf
= 2) for the hydrogen atom.
___________eV
_________ nm
(b) Calculate the wavelength for the three longest wavelengths in
this series.
longest
____________nm
second longest
____________nm
third longest
____________nm
In: Physics
Starting with 2.50 mol of nitrogen gas (N2) in a container at 1.00 atm pressure and 20.0 °C temperature, a student heats the gas at constant volume with 15.2 kJ of heat, then continues heating while allowing the gas to expand at constant pressure, until it is at twice its original volume.
What is the final temperature of the gas?
How much work was done by the gas?
How much heat was added to the gas while it was expanding?
What is the change in internal energy for the whole process?
In: Physics
A small block with mass 0.0400 kg is moving in the xy-plane. The net force on the block is described by the potential- energy function U(x,y)= (5.90 J/m2 )x2-(3.90 J/m3 )y3.
a- What is the magnitude of the acceleration of the block when it is at the point x= 0.29 m , y= 0.66 m ?
b- What is the direction of the acceleration of the block when it is at the point x= 0.29 m , y= 0.66 m ?
In: Physics
A soccer player kicks the ball toward a goal that is 27.6 m in front of him. The ball leaves his foot at a speed of 18.5 m/s and an angle of 31.2° above the ground. Find the speed of the ball when the goalie catches it in front of the net. (Note: The answer is not 18.5 m/s.)
I keep getting a final velocity of 13.92797m/s but its incorrect. Please show your work so I can see what I'm doing wrong.
In: Physics
Internal injuries in vehicular accidents may be due to what is called the "third collision" The first collision is the vehicle hitting the external object. The second collision is the person hitting something on the inside of the car, such as the dashboard or windshield. This may cause external lacerations. The third collision, possibly the most damaging to the body, is when organs, such as the heart or brain, hit the ribcage, skull, or other confines of the body, bruising the tissues on the leading edge and tearing the organ from its supporting structures on the trailing edge.
A) Why is there a third collision? In other words, why are the organs still moving after the second collision?
B) If the vehicle was traveling at 60 mph before the first collision, would the organs be traveling more than, equal to, or less than 60 mph just before the third collision?
Explain your answers in essay form:
In: Physics
A 120 V rms voltage at 60.0 Hz is applied across an inductor, a capacitor, and a resistor in series. If the peak current in this circuit is 0.84840 A, what is the impedance of this circuit?
In: Physics
For two objects dropped at two different times from the same location (e.g. a bridge), while both are still
in free-fall describe how their velocities and their distances change through time (neglecting air
resistance).
An example would be appreciated
In: Physics
In: Physics
A 0.50-kg mass vibrates according to the equation x = 0.35 sin (5.50 t) where x is in meters and t is in seconds. Determine (A) the amplitude, (B) the frequency, (C) the total energy, and (D) the kinetic energy and potential energy when x = 0.3m Please Explain.
In: Physics
(1) A block is placed on a wooden plank, which is initially horizontal. One end of the plank is slowly raised to make it more and more inclined, and for a while the block stays in place on the plank and doesn't slide due to static friction. Finally, when the plank reaches an incline of 56.3o above horizontal, the block begins to slide. What is the coefficient of static friction between the block and the plank?
(2) Continuing the story... after the block begins sliding down the incline at 56.3o, you measure its acceleration down the plank as 7.42 m/s2. What is the coefficient of kinetic friction between the block and the plank?
These will be clicker questions on Wednesday, and we will work together through some problems involving tension and pairs of objects.
In: Physics