Suppose the electric field between the electric plates in the mass spectrometer of Fig. 20-38 is 2.38 ? 104 V/m and the magnetic fields B = B' = 0.66 T. The source contains carbon isotopes of mass numbers 12, 13, and 14 from a long-dead piece of a tree. (To estimate atomic masses, multiply by 1.67 ? 10-27 kg.)
A) How far apart are the lines formed by the singly charged ions
of each type on the photographic film?
mm
(b) What if the ions were doubly charged?
mm
In: Physics
What is the phenomenon of differential negative resistance (negative differential resistance) and how can it be used in electronic devices? Please explain it in two or three paragraphs
In: Physics
A solid, uniform cylinder with mass 8.25 kg and diameter 10.0 cm is spinning with angular velocity 245 rpm on a thin, frictionless axle that passes along the cylinder axis. You design a simple friction-brake to stop the cylinder by pressing the brake against the outer rim with a normal force. The coefficient of kinetic friction between the brake and rim is 0.344.
In: Physics
Pose a situation (only one) problematic of real life, where you need mechanical physics to solve it. Situations similar to those we have been working on in the previous activities
The problem posed must contain the following topics, without being limited to this list:
1. Conservation of Mechanical Energy
2. Conservation of the linear or two-dimensional Moment.
3. Conservation of the angular Moment.
Rubric to evaluate problem-based learning activities PROBLEM-BASED
It shows a real situation, original and with a lot of creativity.
It shows a detailed design of the situation, where it includes all the physical variables contemplated.
The problem situation includes issues of Conservation of mechanical energy, conservation of momentum and conservation of angular momentum.
Shows the calculations evidencing the issues requested for the problem.
In: Physics
A 150-kg satellite is in circular orbit of radius 7.3 Mm around Earth. Determine:(a) potential, kinetic, and total mechanical energies.(b) the orbital speed.(c) the escape velocity from this altitude.
In: Physics
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?
In: Physics
Spectrometer Lab
Summarize this experiment from purpose to procedure to analysis.
Include all important theoretical equations.
{¶ ≤ 100 words}
In: Physics
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
In: Physics
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?
In: Physics
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)?
In: Physics
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:
In: Physics
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?
In: Physics
list at least two weaknesses of using sound to image an object. can these weaknesses be overcome, how?
In: Physics