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Derive Expression Where Needed

1. A motorcyclist is coasting with the engine off at a steady speed 17 m/s but enters a sandy stretch where the coefficient of friction is .80. Will the cyclist emerge from the sandy stretch without having to start the engine if the sand lasts for 15 m. If so, what will be the speed upon emerging? 2. One car has twice the

Work and Energy

Is Work done = average force * displacement= 1/2 kx^2 = 1/2*31*0.02^2 or 1/2*31*0.02?

Weather Forecasts

Question: It is the middle of winter and the weatherman forecasts a cold, overcast, but dry day, with an average temperatures of -2 degrees Celsius. However, he highlights the presence of a strong wind with a wind chill factor that will make it feel like -10 degrees Celsius. What is meant by the term 'wind chill'? How can it be

Elastic and Inelastic Collisions

A 10 gram bullet is fired horizontally into, and becomes embedded in, a suspended block of wood whose mass is 0.890 kg. (a) How does the speed of the block with the embedded bullet immediately after the collision compare with the initial speed of the bullet? (b) If the block with the embedded bullet swings upward and its center

Yet more simple physics

Think about a rollercoaster. If it loaded at a height of about 500m and then dropped down to almost ground level and was followed by 7 circles where the circles height was about the same it would not work well. Explain in terms of kinetic energy, potential energy, etc. why not. (Picture included if needed.)


An ideal gas mixture consists of 3 kg of Ar and 6 kg of CO2 gases. The mixture is now heated at constant volume from 250 K to 350 K. The amount of heat transfer is:

Molecules in vacuum

In an ultra-high vacuum system, the pressure is measured to be 1.00 * 10^-10 torr, the average molecular diameter is 1.00 * 10^-10 m, the average molecular speed is 500 m/s and the temperature is 300 K. Find the number of molecules in a volume of 1.00 m^3 and the mean free path of the molecules.

Mixed Energy Photon Beam

A collimated gamma ray beam consists of equal numbers of 0.1 MeV and 1.0 MeV photons. If the beam enters a 15 cm thick concrete shield, what is the relative portion of 1 MeV photons to 0.1 MeV photons in the emergent beam?

Finding the lagrangian of a system

A triangular piece of wood is free to slide, without friction, in one dimension along a table, forming a moving inclined plane. A block of wood, placed on this inclined plane only moves as the result of the triangular block moving. There is no friction between the triangular piece of wood and the block. Find the lagrangian fo

Electrical Potential Energy

A 100-µF parallel-plate capacitor is charged to 500 V. It is then disconnected from the charging source and insulated. (a) How much energy is stored on the capacitor? (b) If the plates are pulled apart to a separation that is twice their initial separation, what energy is stored on the capacitor? (c) If the answers are not i

Harmonic Oscillator and Wave Packets

Consider the 1-D harmonic oscillator, with Hamiltonian H=p²/2m+½mw²x²=hw(a¬a+1/2), and with energy eigenstates H|n}=En|n}=hw(n+1/2)|n}. The eigenvectors of the annihilation operator a are known as coherent states: a|z}=z|z}, where z is in general a complex number (a is not Hermitian, so z is not necessarily real). Take |z}

Planck's function

Using planck's energy density per unit frequency formula. r(x)= x^3 / e^x -1. Plot r(x) from excel spread sheet and determine its maximum. I need help in using excel to graph this inorder to find the maximum. Then based on the maximum I am supposed to determin planck's constant

Height and Speed on Trapeze

A circus perfomer swings down on a trapeze from a height of 18m (starting from base ground). He picks up an assistant standing on the floor, and just reaches a platform of height h, depositing the assistant on the platform as they reach zero speed together. The performer's mass is 100kg and his assistant's mass is 50kg. The le

Displacement of a Mass on a Spring

a) When the displacement of a mass on a spring is 1/2*A the half of the amplitude, what fraction of the energy is kinetic energy? Express your answer as a percent. b) At what displacement, as a fraction of A, is the energy half kinetic and half potential?

temperature and phase changes in making iced tea

See attached file. Calorimetry involving temperature and phase changes in making iced tea. PSS 17.2: Making the Iced Tea Learning Goal: To practice Problem-Solving Strategy 17.2 for calorimetry problems involving temperature and phase changes. On a hot summer day, you decide to make some iced tea. First, you brew a volum

Physics Problems (Angular Distance; Angular Speed; Tangential Speed etc.)

I would like for you to show me all of your work/calculations and the correct answer to each problem. 11. A jogger on a circular track that has a radius of 0.250 km runs a distance of 1.00 km. What angular distance does the jogger cover in (a) radians and (b) degrees? 15. In Europe, a large circular walking track with a di

Compressive force on rod

The ball has a weight of 15 lb and is fixed to a rod having a negligible mass. If it is released from rest when theta = 0 deg., determine the angle theta at which the compressive force in the rod becomes zero (see attachment for an illustration) answer should be 48.2 deg. Not sure how to get there though.

Force of a Compressed Spring

The collar has a weight of 8lb. If it is released from rest at a height of h= 2ft from the top of the uncompressed spring, determine the speed of the collar after it falls and compresses the spring 0.3ft.

Potential energy

The Great Sandini is a circus performer with mass 60.0 kg who is shot from a cannon (actually a spring gun). You don't find many men of his caliber, so you help him design a new gun. This new gun has a very large spring with a very small mass and a force constant of 1300 N/m that he will compress with a force of 5000 N. The insi

Applying the Conservation Laws

A 2.5 kg block collides with a horizontal spring of negligible mass and spring constant. k=320 N/m. The block compress the spring by 8.5 cm from its rest position. How fast was the block going when it hit the spring if the frictional coefficient between the block and the horizontal surface is 0.40?

Elastic Collision in One Dimension

Two air-track gliders of equal mass are initially moving in the same direction alone a straight line. The rearmost glider has an initial speed of 3.0 m/s and the forward glider has a speed of 2.0 m/s. if the collision is elastic, what are the speeds and directions of the gliders after the collision?

Light Problem Set

1. (a) What are the wavelength and color of the line in the Balmer spectrum for n2=4? (b) What are the wavelength and color of the line for n2=5? a. a) 486.08 nm and blue b) 434.00 nm and violet b. a) 686.08 nm and red b) 634.00 nm and red c. a) 386.08 nm and ultra violet b) 334.00 nm and ultra violet d. a) 5

Multiple Choice Questions-Light

1. A myopic person wears eyeglasses with a lens strength of - 3.5 diopters. Where is the far point for that person's eyes? a. 3.5 m b. 25 cm c. 28.6 cm d. infinity 2. Red light of wavelength 632.8 nm is incident on a pair of slits whose separation is 0.75mm. What is the separation of neighboring interfer

Package sliding down chute: determine speed and force of the package

See attached file. The package has a weight of 5lb and slides down the chute. When it reaches the curved position, AB, it is traveling at 8ft/s (theta= 0 deg). If the chute is smooth, determine the speed of the package when it reaches the intermediate point C (theta = 30 deg) and when it reaches the horizontal plane (theta= 4

Calculating elastic potential energy

A 3.2 kg block is hanging stationary from the end of a vertical spring that is attached to the ceiling. The elastic potential energy of this spring/mass system is 1.6 J. What is the elastic potential energy of the system when the 3.2 kg block is replaced by a 5.6 kg block?

Calculating speed as a function of distance

The scheme presents two blocks: The first, Block A, is on a table. Block A is attached to an end of a string. At the end of the table, there is a pulley; the string passes by this pulley, then becomes vertical. At the other end of this string (end of this vertical string) there is Block B. So Block A is attached to Block B by

Coefficient of Kinetic Friction.

Please do not put your response in a .pdf format, but Word documents are okay. Thanks! A sled is being held at rest on a slope that makes an angle theta with the horizontal. After the sled is released, it slides a distance d_1 down the slope and then covers the distance d_2 along the horizontal terrain before stopping. Find t

A partially inelastic collision

3.) A car of mass 1148 kg has kinetic energy of 117 kJ. The driver sees a stalled SUV of mass 2700 kg blocking the intersection. Because he is having a bad hair day, the driver plows into the SUV without braking. The two vehicles stick together (a perfectly inelastic collision) and slide to a stop. a) How much work is done a