The potential difference from the cathode (negative electrode) to the screen of an old television set is +22,000 V. An electron leaves the cathode with an initial speed of zero.

a)Determine the kinetic energy of the electron.

b)Determine the speed of the electron.

Chuck and Jackie stand on separate carts, both of which can slide without friction. The combined mass of Chuck and his cart, mcart, is identical to the combined mass of Jackie and her cart. Initially, Chuck and Jackie and their carts are at rest. Chuck then picks up a ball of mass mball and throws it to Jackie, who catches it. Assume that the ball travels in a straight line parallel to the ground (ignore the effect of gravity). After Chuck throws the ball, his speed relative to the ground is vc. The speed of the thrown ball relative to the ground is vb. Jackie catches the ball when it reaches her, and she and her cart begin to move. Jackie's speed relative to the ground after she catches the ball is vj. When answering the questions in this problem, keep the following in mind: The original mass mcart of Chuck and his cart does not include the mass of the ball. The speed of an object is the magnitude of its velocity. An object's speed will always be a nonnegative quantity.

Discuss the discoveries that LIGO has made. Why are these discoveries considered to be direct detection of gravitational waves?

A smooth circular hoop with a radius of 0.600 m is placed flat on the floor. A 0.450-kg particle slides around the inside edge of the hoop. The particle is given an initial speed of 9.50 m/s. After one revolution, its speed has dropped to 4.50 m/s because of friction with the floor.

(a) Find the energy transformed from mechanical to internal in the particle—hoop—floor system as a result of friction in one revolution.

_____J

(b) What is the total number of revolutions the particle makes before stopping? Assume the friction force remains constant during the entire motion.

_____rev

An attacker at the base of a castle wall 3.75 m high throws a rock straight up with speed 8.50 m/s from a height of 1.50 m above the ground.

(a) Will the rock reach the top of the wall?

(b) If so, what is its speed at the top? If not, what initial speed must it have to reach the top?

(c) Find the change in speed of a rock thrown straight down from the top of the wall at an initial speed of 8.50 m/s and moving between the same two points.

(d) Does the change in speed of the downward-moving rock agree with the magnitude of the speed change of the rock moving upward between the same elevations?

(e) Explain physically why it does or does not agree.

I tried to ask this question before, but got the wrong answer. I know for a, the answer is yes. I can't figure out the rest. Thanks!

1. Why is the conductivity of metal different from the insulator? - How different is the semiconductor from them?

2. What is the main cause of the energy gap? How is it related to the Bragg condition.

3. How is Bloch function different from the general wavefunction?

What do you think a dream yard for kids? What would they like to do there? What kinds of things should this yard have? Why? Explain your thoughts.

what are some pros of using solar energy over fossil fuels?

A 5.34g bullet leaves the muzzle of a rifle with a speed of 348 m/s. What force (assumed constant) is exerted on the bullet while it is traveling down the 0.812 m long barrel of the rifle?

The concepts in this problem are similar to those in Multiple-Concept Example 4, except that the force doing the work in this problem is the tension in the cable. A rescue helicopter lifts a 76.8-kg person straight up by means of a cable. The person has an upward acceleration of 0.500 m/s² and is lifted from rest through a distance of 8.64 m. (a) What is the tension in the cable? How much work is done by (b) the tension in the cable and (c) the person's weight? (d) Use the work-energy theorem and find the final speed of the person.

In this Topic, you have learned the terms used to describe motion (e.g., distance, speed, and acceleration) as well as Newton's laws explaining motion. Describe at least two ways the material you have learned in this unit applies to driving a car (refer to the Arizona Driver License Manual located within the weekly readings). Has what you have learned in this Topic changed how you drive? If so, please explain.

The figure shows 3 point charges at the corners of a rectangle. The top left corner is positive 10nC and the bottom left corner is 5 nC they are both positive. The top side is 3cm while the right side is 4cm the bottom and the left sides are also the same. The top right corner is -10 nC. A -15nC charge is placed at the emply corner that being the bottom right.

A) find the electric potential at the center of the rectangle

B) find the electric potential energy of the configuration.

Useful physical constants: g = 9.80 m/s2

1. At a baseball game in a large stadium with seats surrounding the outfield, a batter hits a “home run” up into the seats. The ball lands at a height above the height at which it was hit.

The ball is hit with an initial velocity of 43.0 m/s at an angle of 40.0 ̊ above the horizontal, and it takes 5.00 s to land. Ignore the effect of air resistance throughout this problem.

a. Decompose the ball’s initial velocity, v0, into its x- and y- components, v0x and v0y. Calculate the numerical value of both components. Choose the +y-direction to be upward and the +x-direction to be downrange. Show your work.

b. What is the baseball’s total horizontal displacement, from hit to landing? Show your work.

c. What is the maximum vertical displacement that the ball reaches during its trajectory? Show your work completely.

1. The potential energy of an object attached to a spring is 2.80 J at a location where the kinetic energy is 1.50 J.1.50 J. If the amplitude ?A of the simple harmonic motion is 20.0 cm, calculate the spring constant k and the magnitude of the largest force Fspring, max that the object experiences.

k = ??? N/m

F spring, max = ??? N

2. The spaceship Intergalactica lands on the surface of the uninhabited Pink Planet, which orbits a rather average star in the distant Garbanzo Galaxy. A scouting party sets out to explore. The party's leader–a physicist, naturally–immediately makes a determination of the acceleration due to gravity on the Pink Planet's surface by means of a simple pendulum of length 1.37 m. She sets the pendulum swinging, and her collaborators carefully count 104 complete cycles of oscillation during 208 s. What is the result?

acceleration due to gravity = ??

An object with a high density can be floated on an object with a low density in a fluid with a density if the volumes of the objects are right. What is the condition for such a stack having neutral buoyancy, in terms of masses and volumes of the blocks and the density of the water? Express the condition mathematically.