Questions
Suppose we have the following vectorial equation c = na x b where n is a...

Suppose we have the following vectorial equation c = na x b where n is a constant, and c, a, b are vectors Givens n = -1 a = 2i – j

a) Determine the direction and size of the vector c if b = 2i

b) Determine the direction and size of the vector c if b = 2k

c) Determine the direction and size of the vector c if b = 2i – k

I really need the step by step for this. If you could, please write legibly.

Thank you Greatly!

In: Physics

1. Describe the Velocity vector and Acceleration vector of ball being thrown straight up in the...

1. Describe the Velocity vector and Acceleration vector of ball being thrown straight up in the air and then coming back down.

2. A tennis ball is being swung around in a circle in uniform circular motion. Describe the direction of the linear velocity vector, the linear acceleration vector, and the centripetal (radial) acceleration vector.

3. Which pulls harder gravitationally, the Earth on the Moon, or the Moon on the Earth?

4. If I double the force I apply pushing on a crate as it moves across a frictionless surface, what happens to it's Normal Force?

please 1-4

In: Physics

in this problem we are interested in the time-evolution of the states in the infinite square...

in this problem we are interested in the time-evolution of the states in the infinite square potential well. The time-independent stationary state wave functions are denoted as ψn(x) (n = 1, 2, . . .).

(a) We know that the probability distribution for the particle in a stationary state is time-independent. Let us now prepare, at time t = 0, our system in a non-stationary state

Ψ(x, 0) = (1/√( 2)) (ψ1(x) + ψ2(x)).

Study the time-evolution of the probability density |Ψ(x, t)|^2 for this state. Is it periodic in the sense that after some time T it will return to its initial state at t = 0? If so, what is T? Sketch, better yet plot (by using some software), |Ψ(x, t)|^2 for 3 or 4 moments of time t between 0 and T that would nicely display the qualitative features of the changes, if any.

(b) Let us now prepare the system in some arbitrary non-stationary state Ψ(x, 0). Is it true that after some time T, the wave function will always return to its original spatial behavior, that is,

Ψ(x, T) = Ψ(x, 0)

(perhaps with accuracy to an inconsequential overall phase factor)? If so, what is this quantum revival time T? Compare to (a). And why do you think it was possible to have it in this system for an arbitrary state?

(c) Think now about the revival time for a classical particle of energy E bouncing between the walls. Assuming the positive answer to (b), if we were to compare the classical revival behavior to the quantum revival behavior, when these times would be equal?

Need help with Part C!

In: Physics

Design a carefully scaled and drawn Minkowski diagram depicting two reference frames P (x and t)...

Design a carefully scaled and drawn Minkowski diagram depicting two reference frames P (x and t) and Q (x' and t') with Q moving at a speed of 0.6c in the positive x-direction with respect to P.

i) If event A occurs at x=1 and t=1 while event B occurs at x=1 t=2, determine the interval of time between these events as measured by an observer in Q. Suggest two other events and use them to demonstrate reciprocity of time dilation. Show the space-time interval is the same for P and Q

ii) If a meter stick is at rest in Q between x=1 and x=2, determine the length measured by an observer in P.

In: Physics

If I have a positively charged surface and bring it near to a plasma, what would...

If I have a positively charged surface and bring it near to a plasma, what would happen? Will both the electrons and protons behave in the same way? (compare their accelerations).

In: Physics

at the beginning, a stagnant bomb explodes and breaks into 3 pieces.in this case a)is linear...

at the beginning, a stagnant bomb explodes and breaks into 3 pieces.in this case a)is linear momentum maintained?please explain. b) is kinetic energy conserved? please explain.

In: Physics

On a planet, the acceleration due to gravity is only 7.2 m/s2. A person living on...

  1. On a planet, the acceleration due to gravity is only 7.2 m/s2. A person living on that planet throws a football at 10 m/s at an angle of 48 degrees to the horizontal. The person is standing, so the ball launches from an initial height of 1.8 meters above the ground. (Ignore any air resistance here.)

  1. What maximum height from the ground would the ball reach?
  2. What would be the flight time before the ball gets back to the ground?

In: Physics

Explain the method of determining the charge-to-mass ratio (e/m) in the Thomson experiment.

Explain the method of determining the charge-to-mass ratio (e/m) in the Thomson experiment.

In: Physics

An interstitial in the lattice structure puts the surrounding bonds lattice in tension or compression? How...

An interstitial in the lattice structure puts the surrounding bonds lattice in tension or compression? How does this stress affect movements of dislocations? Use figures/schematics to explains.

In: Physics

Explain the model of blackbody. Present and explain Wien’s and Stefan’s laws regarding the blackbody radiation....

Explain the model of blackbody. Present and explain Wien’s and Stefan’s laws regarding the blackbody radiation. Explain Planck’s hypothesis of energy quanta.

In: Physics

what is the angular separation between a star at Right Ascension 6hr and Declination 60 degrees...

what is the angular separation between a star at Right Ascension 6hr and Declination 60 degrees and another star at Right Ascension 0hr and Declination 60 degrees? and also please explain what is angular separation?

In: Physics

Derive the barometric formula which shows in an isothermal atmosphere the pressure as a function of...

Derive the barometric formula which shows in an isothermal atmosphere the pressure as a function of height.

In: Physics

Choose the correct answer/s. 1.) In an interference experiment, monochromatic light from a laser is passed...

Choose the correct answer/s.

1.) In an interference experiment, monochromatic light from a laser is passed through two parallel slits separated by d.  An interference pattern is formed on the screen placed at a distance R from the screen. If the separation distance between the slits is doubled, which of the following is true?

The distance of a particular dark fringe from the central bright fringe will be doubled.

The wavelength of light will be doubled.

The distance of a particular bright fringe from the central bright fringes will be doubled.

The length of the central bright fringe will be halved.

2.)

Which of the following statements is NOT true about a double-slit interference pattern?

The bright fringes are longer than the dark fringes.

Adjacent bright fringes have approximately equal brightness / intensity.

The dark fringes are equally-spaced.

The bright fringes are equally spaced.

3.)

If you compare the single-slit pattern and the double-lit pattern, which of the following is correct?

There are more bright fringes in the double-slit pattern compared to the single-slit pattern.

There are more dark fringes in the single-slit pattern compared to the double-slit pattern.

The dark fringes in the double-slit pattern are equally spaced while the dark fringes in the single-slit pattern are not equally spaced.

The bright fringes in the double-slit pattern are equally spaced while the dark fringes in the single-slit pattern are not equally spaced.

8.)

In a diffraction experiment, monochromatic light from a laser is passed through a slit of width a.  A diffraction pattern is formed on the screen placed at a distance x from the screen. Which of the following statements is true?

The central bright fringe is twice as long as the other bright fringes.

The positions of dark fringes vary inversely with slit-screen separation.

The central bright fringe and the other bright fringes have the same brightness / intensity.

The positions of the dark fringes vary directly with the slit-width.

In: Physics

an 10 kg object is hung from a spring attached to a fixed support. The spring...

an 10 kg object is hung from a spring attached to a fixed support. The spring constant of the spring is k=40 Nm**(-1) (I mean to the power of -1) Suppose an external downward force of magnitude f(T) = 20 e **(-2t) N is applied to the object, and damping due to air resistence occurs with damping constant beta = 40 N s m **(-1). Let y(t) denote the distance in meters of the object below its equilibrium position at time t seconds. Take the gravitational constant to be g=9.8 m.s**(-2). a) Draw a diagram of the system, showing all forces acting on the object, assuming object is above the equilibrium position and moving down. Include the direction and magnitude of each force.

b) state the equation of motion of object.

c) Find the general solution to the equation of motion.

d) Assume that the object initially starts at the equilibrium position with the velocity of 2 m.s**(-1) upwards

i. Find the position of the object at any time.

ii. At what times, if any, is the object located at its equilibrium position?

In: Physics

1-What four physical factors affect the resistance of a wire? 2-A wire of uniform cross-section has...

1-What four physical factors affect the resistance of a wire?
2-A wire of uniform cross-section has a resistance of R. What would be the resistance of a similar wire, made of the same material, but twice as long and of twice the diameter?
3- A block of carbon, 1.0 cm by 2.0 cm by 5.0 cm, has a resistance of 0.015 Ω between its two smaller faces. What is the resistivity of carbon?
4-What length of German silver wire, diameter 0.050 cm, is needed to make a 28 Ω resistor, if the resistivity of German silver is 2.2 x 10-7 Ω.m?
5-What is the resistance of one kilometer of copper wire (copper resistivity is 1.68x10-8 Ω.m), with a diameter of 10 cm.

In: Physics