A 52 cm long thin string is attached to a 25 g mass. You bring the mass up until you make a 4.2◦ angle with respect to the equilibrium position and let go. You start the timer when the simple pendula has a 2.1◦ angle with respect to the equilibrium position. (a) What are the equations for the position, velocity, and acceleration of the system? (b) Using your equations, determine what the three will equal at the instant you let go, and 3.0 s after you let go. Assume no damping occurs.

What is the reason for the seasons? Explain fully why different hemispheres experience opposite temperatures at some times of the year and similar temperatures at others. Identify the months when these events occur.

An n-type silicon wafer undergoes a pre-deposition diffusion process with a constant surface concentration of boride gas; the resulting concentration of boron in silicon at the surface is estimated to be 1x1018 atoms cm-3. The background concentration of trace boron atoms in the silicon wafer is estimated to be 1x1014 cm-3. (A) Estimate the depth of the p-n junction below the surface when the background doping concentration of the n-type impurity is 3.45 x1016 cm-3; assume the diffusion process proceeds for 10 minutes and has a diffusion parameter given by 10-12 cm2 s -1. (B) Estimate the number of boron atoms (per cm^2) introduced in this thin surface layer following the pre-deposition step.

1. Choose the scenario under which each of the following Doppler shift effects will be seen:

choices are:

The source and observer are approaching one another

The source and observer are moving away from one another

The source and observer are stationary relative to one another

1.1 Light is shifted towards the blue end of the spectrum (blue-shifted).

1.2 The apparent pitch of the source is lower than the actual pitch of the source.

1.3 There is no apparent change in the pitch or color.

1.4 Light is shifted towards the red end of the spectrum (red-shifted).

1.5The apparent pitch of the source is higher than the actual pitch of the source.

2.Sounds coming from moving objects, such as the siren of an emergency vehicle, appear to change pitch as the object moves toward or away from you. Compare the frequency of a siren based on its motion toward or away from you.

rate from  highest to lowest

away from you 31 miles per hour

toward you at 34 miles per hour

away from you at 34 miles per hour

toward you at 55 miles per hour

neither toward nor away from you

toward you at 3 miles per hour

A car with inertia 1500kg is driving down a one-way street at 15 m. An unobservant s

driver of a 2000kg pickup truck is driving the wrong way down the street at −10 ms , and runs head on into the car. (Assuming the system consists of the car and the truck only)

a) What is the velocity of the car after the collision if the velocity of the truck is 5 ms ?

b) What is the coefficient of restitution for this collision? What type of collision is this?

c) What is the velocity of center of mass of the system?

d) Find the center-of-mass kinetic energy for the system.

e) What is convertible kinetic energy of the system before the collision?

6. f) What is the minimum amount of energy required to conserve the momentum of the system?

7. g) What is the total kinetic energy of the system before the collision?

8. h) What is the total kinetic energy of the system after the collision?

i) What is the change in kinetic energy of the system due to this collision? Since energy cannot be destroyed, explain what happens to this energy.

5. A giant lollipopconsists of a 280gram 14cm diameter disk on the end of a 40 gram 25cm long stick. A child is balancing a GIANT lollipop on the end of her finger.

a. What is the moment of inertiaof the lollipop about the end balanced on the childs finger?

b. If the child holds the lollipop from the end of the stick at and angle of 30o abovethe horizontal, what are the forcesthey must exert on the stickto keep it in equilibrium?

c. If the childlets loose her grip so that the lollipop begins to rotatein her handfrom the 30o position, what is the instantaneous angular acceleration of the lollipop?

Describe static and dynamic methods of determining the force constant of a spring.

briefly describe how different characteristic of motion are reflected by Position vs. time graphs and Velocity vs. time graphs

Looking at a football match, which of the following describes an event CONSISTENT with the study of Classical Mechanics?

a) The ball gains speed by bouncing into a puddle after a player kicks.

(b) A ball leaves the player's foot without rotation and, after colliding with the crossbar, returns to the player's feet faster than at the start of the kick.

c) In a soccer game, there is no mechanical phenomenon related to the study of physics.

d) The fact that the boot is of large or small nails, of metal or plastic, making the player slip more or less on rainy days, concerns the study of universal gravitation.

e) The encounter between a player's boot and the ball at the time of the kick is an example of a partially elastic shock in which there is a transfer of energy and momentum. ”

Analyzing the alternatives of the above question, we can observe in item “a” a phrase widely used by narrators and sports commentators in their radio and TV broadcasts. This phrase contains one of the many conceptual distortions in physics presented in sports broadcasts. Research and present in the COLLABORATIVE CHALLENGE other phrases that exemplify the extremely distorted view of physics.

How could we justify the goalkeeper's difficulty catching a kick in a rainy soccer match? Review the examples presented by your colleagues and indicate the misconceptions in the sentences. What do you think is the convincing power that a statement of this size can inadvertently wield in the minds of sports aficionados?

A pendulum with a length of 35 cm swings back and forth as shown in the figure above, at each turn around point it stops and it starts accelerating until reaching maxium velocity at the botton (equilibrium position), at which point it starts slowing down. If the maximum angle is 48 degrees, what is its maximum velocity in m/s? (Use g = 10.0 m/s2 and assume there is no friction)

1. A particle satisfying the time-independent Schrodinger equation must have

a) an eigenfunction that is normalized.

b) a potential energy that is independent of location.

c) a de Broglie wavelength that is independent of location

d) a total energy that is independent of location.

Correct answer is C but I need detailed explanation

also explain each point why they are false

let R be a region bounded by x = 0 and x =1 and y = 0 and y = 1. Suppose the density is given by 1/y+1.Notice that R is denser near the x axis. As a result we might expect the centre of mass to be below the geometric center(1/2,1/2). Also since the density does not depend on x we do expect moment of inertia about the x axis to be 1/2. verify the moment of inertia about x is 1/2 and compute the value of the moment of inertia about the y axis

Describe the Drude model and the Sommerfeld model: the difference and the similarity, the successes and the failures of each model.

A 45 kg wooden crate is being pushed across a wooden floor with a force of 175 N. If, uk = 0.03. What is the acceleration of the crate?

6. Why do you think the inside of a car feels so much warmer than its surroundings on sunny days? a. How can you use the sim to test your ideas? b. Describe your experiment and state some evidence that explain the different temperatures on a microscopic level using photons.