PH 203 Recitation Homework Summer 2011

Chapter 20 (due 08/17)

An electron is initially moving to the right at 2.50 x 10⁶ m/s. It enters a region of space where there is a constant electric field of magnitude 0.125 mN/C and directed upward. (a) In which direction will the electron accelerate? Explain. (b) What will be the shape of the electron's trajectory? (c) During a certain amount of time in the electric field, the electron moves 25.0 cm to the right. How far does it move vertically during this time?

Chapter 21 (due 08/18)

There is an equilateral triangle with one point charge at each vertex. The point charges have charges of -Q, +3Q and -4Q respectively. The length of one side of the triangle is L. Determine an expression in simplest form for the electric potential at a point halfway between the -Q and +3Q point charges. Simplest form means that the answer is factored completely and consists of only one simple fraction.

Chapter 22 (due 08/19)

A circuit consists of a resistor of resistance R connected across the terminals of a battery. The current through the resistor is 5.00 A in this configuration. When another resistor of resistance 8.00 ohms is inserted into the circuit in series with the other resistor, the current decreases to 2.00 A. What is the resistance R?

Chapter 23 (due 08/24)

An unknown number of identical capacitors, each having a capacitance of 8.00 mF are connected in parallel and then the combination is connected across the terminals of a battery with an EMF of 10.0 V. After the circuit reaches equilibrium and electrons no longer move out of the battery and into the capacitors, the amount of energy stored in the circuit is 6.40 J. How many capacitors are in the circuit?

Chapter 24 (due 08/25)

A source produces ⁶Li ions, which have an electrical charge of +1.60 x 10^-19 C and a mass of 9.99 x 10^-27 kg. The ions are accelerated from rest through a potential difference of 25.0 kV and pass horizontally into a region in which there is a uniform magnetic field of magnitude 1.20 T in the vertical direction. What is the diameter of the circle around which the ⁶Li ions consequently move?

Chapter 25 (due 08/26)

Sunlight just outside the Earth's atmosphere has a maximum intensity of 2.76 kW/m². What are the maximum magnitudes of the electric and magnetic fields for sunlight at this location?

Chapter 17 (due 08/31)

The distance between the centers of adjacent openings in a diffraction grating is 0.0100 mm. A viewing screen is 1.00 m from the grating. The bright fringes near the center of the screen are spaced apart by 4.50 cm. What is the wavelength of the light?

Chapter 18 (due 09/01)

An object is located 0.250 m from a concave mirror. When viewed in the mirror, its image is inverted and is twice as tall as the object. What is the radius of curvature of the mirror?