Electricity and Magnetism Answers

How can you magnetize an iron bar of the Earth is the only magnetic around?

Are there any locations in the United States where a magnetic compass will point to the geographic north pole?

Three point charges are arranged along the y-axis in a vacuum. The topmost charge bears a charge of -4.0 µC, the middle charge has a charge of +3.0 µC, and the bottom one carries a -7.0 µC charge. What is the magnitude and direction of the net electrostatic force that the middle charge experiences?  

An electron (m = 9.11 x 10^-31kg, q = 1.60 x 10^-19C) at rest is accelerated through an electric potential difference of 12.0 V. It then enters a uniform magnetic field of 0.100 T [up], when initially moving [N].

a) Find the initial speed of the electron entering the magnetic field.

b) Find the magnetic force on the electron entering the magnetic field.

c) Find the radius of the circular path of the electron in the field. 

Two stationary frictionless pucks are placed on a level surface at an initial distance of 3.0m. The mass of puck 1 is 0.55kg and it has a charge of

+5.0 x 10^-4C,

while puck 2 has a mass of 0.25kg and a charge of +3.5 x 10^-4C. Find the velocity of each puck after they have moved very far apart.

The radius of the earth s 6.38 x 106m. If a satellite is in orbit around the earth at an altitude of 1500km, what is the speed of the satellite? 

Mass 1 is five times as large as mass 2. Both masses area at rest and are separated by 150 m.

Where could you place a third mass, mass 3, if the net force on mass 3 must be zero?

The expression of the electric field associated with an electromagnetic wave in vacuum is given by

E = (1000 Vm^-1) z sin (2π x 10^8 t + kx)

Determine the wave number, frequency, the direction of propagation and the magnitude and direction of the magnetic field associated with the wave

A transverse sinusoidal wave is generated at one end of a long horizontal string by a bar which moves the end up and down through a distance of 0.5cm. The motion is continuous and is repeated continuously 150 times per second.

a) If the string has a linear density of 0.25 kg.m-1 and is kept under a tension of 90N, determine the

i) speed

ii) Amplitude

iii) Frequency and

iv) Wavelength of the wave in motion

what is the expression of the medium's particle velocity as the waves pass by them