Share
Explore BrainMass

Energy

Speed

A stone is dropped from a height of 100m. At what height is half of its energy potential and half kinetic? What is the speed of the stone at this height?

Power Output

Approximately 4X10^9kg of matter is converted into energy each second in the sun. Find the power output of the sun.

Electronics problems involving capacitor, resistor etc.

1) A tungsten filament has a resistance of 3 OMP at 20 degrees. When connected to a 100V power supply a current of 6.0A passes through a filament. If the filament is connected to the same power supply when it is at 2000 degrees, what will be the current through the filament and its power loss? 2) A battery whose emf is

Physics: Velocity of the ball assuming mechnaical energy is conserved

A plank of length 2l and mass M lies on a frictionless plane. A ball of mass m and speed Vo strikes its end (the plank is standing vertical and the ball strikes the top from the left). Find the final velocity of the ball, Vf, assuming that mechanical energy is conserved and that Vf is along the original line of motion. b)Fin

Yo-yo Tension and Average Force on the String

A yo-yo of mass M has an axle of radius b and a spool of radius R. Its moment of inertia can be taken to be MR^2/2 and the thickness of the string can be neglected. The yo-yo is released from rest. a) What it the tension in the cord as the yo-yo descends and as it ascends? b) The center of the yo-yo descends distance h be

Kinetic energy applied to a roll of paper towel with force

See attached file. A roll of paper towels is a uniform hollow cylinder, mass M=.75 kg, outer radius Ro=.084 m, inside radius of the hollow core Ri=.036 m. The roll is mounted on frictionless bearings. See attachment #1 for a picture showing parameters. By pulling on the paper towel with a tangential force P=.25 nt, sta

Energy

A spring is compressed by 0.0800m and is used to launch an object horizontally with a speed of 2.40 m/s. If the object were attached to the spring, at what angular frequency (in rad/s) would it oscillate?

Rotational Motion

A small marble is rolling on the inside of a parabolic bowl whose surface is given by z = ®r2 in cylindrical polar coordinates. There is no friction, but the gravity is pulling down (in the negative-z direction). Consider the most general case where the marble is free to move in any direction on the surface. (a) Identify all

A Particle Moving In One Dimension

A particle of mass m moves in one dimension along the positive x axis. It is acted on by a constant force directed toward the origin with magnitude B, and an inverse square law repulsive force with magnitude A/x^2. a) Find the potential energy function U(x) b) Sketch the energy diagram for the system when the maximum kineti

Energy conservation using centripetal motion.

A roller coaster has an initial speed of 9.50 m/s at the top of the first hill, which is 44.00 m above the ground. Neglecting friction, what will be the speed of the roller coaster at the top of the next hill, which is 26.00 m above the ground?

Calculating the loss of mechanical energy.

A block of mass M slides along a horizontal table with speed Vo. At x=0 it hits a spring constant k and begins to experience a frictional force. The coefficient of friction is a variable and is given by u=bx, where b is a constant. Find the loss in mechanical energy when the block has come momentarily to rest.

Initial velocities of two particles

Two particles, of mass 1 kg and 3 kg, are traveling towards each other with velocities of 100 m/s and -40 m/s respectively. Using the laws of physics (e.g. conservation of energy & momentum) calculate the following: a) What are the initial energies of the particles? b) What are the final velocities of the particles? c) Wh

Determining the color of salt when it is thrown into a flame.

The lowest lying excited state of sodium is 2.104 eV above the ground state. Given that Planck's constant is 4.135x10 (to the negative 15 pwr.) eV/Hz, what color of light do you expect sodium atoms to give off? Table salt is the crystal sodium-chloride NaCl. If you have a gas burner in your kitchen, take some salt and throw it