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Springs and Inclined Planes

1. A light horizontal spring has a force constant of k=100 N/m. A 2.00 kg block is pressed against one end of the spring, compressing it 0.100 m. When the block is released from rest it moves 0.250 m to the right of release position. Show that the coefficient of kinetic friction between the block and the horizontal surface is

DC Circuits: Energy and Current

Assume that the length of an axon membrane of about 10 cm is excited by an action potential (length excited = nerve speed x pulse duration = 50 m/s x 2.0 ms = 10 cm). In the resting state, the outer surface of the axon wall is charged positively with K+ ions and the inner wall has an equal and opposite charge of negative org

Work and Kinetic Energy

The spring of a spring gun has force constant k = 400 N/m and negligible mass. The spring is compressed 6.00 cm and a ball with mass 0.0300 kg is placed in the horizontal barrel against the compressed spring. The spring is then released, and the ball is propelled out the barrel of the gun. The barrel is 6.00 cm long, so the ball

Energy stored in capacitor

Consider a parallel plate capacitor with area A and separation d. The plates have fixed charges Q and -Q, and no battery connected. Determine the energy stored before and after the insertion of a dielectric with dielectric constant K that completely fills the space between the plates.

Parallel plate capacitor: Find the energy stored

1. Consider a parallel plate capacitor, fixed area A, and fixed separation, d. Find the energy stored, and after insertion of a slab of dielectric, which completely fills the space between the plates for each of the two cases (a) The plates are connected to a battery which maintains constant potential difference (b) The pl

Free-Falling Bodies - Pellet Gun Question

If a gun is fired straight downward from the edge of a cliff that is 17 m above the ground and the pellet strikes the ground with a speed of 25 m/s. How do you determine how far above the cliff edge that the pellet would have to have gone if the pellet had been fired straight upward

Energy in Thermal Motion

A combination of 0.250 kg of water at 20.0 degrees C, 0.400kg of aluminum at 26.0 degrees C, and 0.100 kg of copper at 100 degrees C is mixed in an insulated container and allowed to come to thermal equilibrium. Neglect any energy transfer to or from the container and determine the final temperature of the mixture.

Energy required to create a rabbit "out of thin air".

This figure indicates the energy required to conjure up the rabbit "out of thin-air". Evidently it takes more than energy, U=E, of the rabbit. Please explain, and also tell me why these energies are called "Free". In other words, why did scientists give them such a name? Which figure is correct or are they both correct ?

Oscillations, Frequency, Waves, Doppler Effect, etc

1. A 2kg block is attached to a spring and placed on a horizontal smooth surface. A horizontal force of 20N is required to hold the block at rest when it is pulled .2m from its equilibrium position. The block is released from its rest from this point, and is subsequently undergoes simple harmonic motion. Find a) the spring st

Temperature and Heat of Metal

A metal ball of mass 0.65 kg with initial temperature of 30 oC is dropped into a container of 1.29 kg of water at 20 oC. If the final temperature is 20.4 oC, what is the specific heat of the metal to the nearest tenth of a J/kg·K?

Frequency of Motion

Solid, uniform cylinder of mass m and radius R is fitted with a frictionless axle along the cylinder's long axis. A horizontal spring (spring constant k) is attached to this axle. Under the influence of the spring, the cylinder rolls back and forth without slipping on a horizontal surface. What is the frequency of this motion?

Solving for the Kinetic Energy

A thin hoop with a radius of 10 cm and a mass of 3kg is rotating about its center with an angular speed of 3.5 rad/s. What is its kinetic energy?

Solving for Height

An 11 kg bowling ball is dropped into a tub containing a mixture of ice and water. A short time later, when a new equilibrium has been established, there are 5.0 g less ice. From what height was the ball dropped? Part A Assume the bowling ball has an initial temperature of 0 degreesC, and that no water or ice splashes out.

Block Problems

1) A stationary block explodes into two pieces that slide along a frictionless floor and then into regions with friction, where they stop. The first piece, with a mass of 2.0 kg, encounters a coefficient of kinetic friction of 0.40 and slides to a stop in a distance 0.15 m. The second piece encounters a coefficient of kinetic fr

Proton with Energy

(See attached file for full problem description) --- - Proton with energy 1.3 MeV is moving along a straight line ("0 degrees" in the figure) in the vacuum tube...


Photo-tubes cut off (don't respond to photons) at sufficiently small wavelengths. This is because the photo-tube's glass does not transmit UV. They also cut off at sufficiently large wavelengths, where the glass does transmit the light. Why?

Energy and momentum: Rolling, Collision and project.

The task is to determine where the metal ball will land. First ball will begin at rest and travel through a track and elastically collide with the metal ball. This metal ball will then is defenestrated and drop down. Also determine where the metal ball will land. Clear explanation of each step is needed. When it is done, it is a

Potential energy and waves

A pulsed laser produces brief bursts of light. One such laser emits pulses that carry 0.350J of energy but last only 225fs. a) What is the average power during one of these pulses? b) Assuming the energy is emitted in a cylindrical beam of light 2.00mm in diameter, calculate the average intensity of one of the pulses? c) W

Rotational Inertia Problem

A uniform solid sphere of mass 5 kg and radius of 30 cm is rotating about an axis through its center at a rate of 180 rev/min. Find the kinetic energy of the sphere. The rotational inertia of the sphere is 2/d MR^2.

Rotational Motion: Rod released on smooth horizontal plane

A thin rod of length h and mass M is held vertically with its lower end resting on a frictionless horizontal surface. The rod is then released to fall freely. Determine the speed of its center of mass just before it hits the horizontal surface. Use h, M, and g for length, mass, and gravitational acceleration respectively. (b)

3 Physics Problems

(See attached files for full problem description with units and diagrams) --- A package of mass is released from rest at a warehouse loading dock and slides down a 3.0-m-high frictionless chute to a waiting truck. Unfortunately, the truck driver went on a break without having removed the previous package, of mass 2 , from