Subterm 2 - Study Guide

Physics CP

You may bring an 8.5”x11” page of notes to the final. The notes must be on ONE SIDE only, completely unique, your own work and in your OWN HANDWRITING.

Waves/Sound

  1. A person on a pier observes a set of incoming waves with a distance of 1.6 m between crests. A wave laps against the pier every 4.0 s. (a) What is the frequency of the waves? (b) What is the speed of the waves? (0.25 Hz, 0.4 m/s)
  1. A pipe open at both ends has a fundamental frequency of 300 Hz when the temperature is 100°C. What is the length of the pipe assuming the speed of sound is 387 m/s? (0.64 m)
  1. Transverse waves with a speed of 50.0 m/s are produced on a stretched string. If the waves have a wavelength of 0.75 m, what is their frequency? (67 Hz)
  1. What is resonance? Give some examples.
  1. A sound wave traveling at 335 m/s is emitted by a foghorn of a tugboat. An echo is heard 3.55 second later. How far away is the reflecting object? (595 m)
  1. A commuter train passes a passenger platform at a constant speed of 35 m/s. The train horn is sounded at a frequency of 378 Hz when the train is at rest. (a) what is the frequency observed by a person on the platform as the train approaches and (b) as the train recedes from him? (c) What wavelength does the observer find in each case? (assume the speed of sound is 345 m/s) (421 Hz, 343 Hz, 0.819 m, 1.01 m)
  1. The power output of one mosquito is 7.5x10-10 W. (a) How far from your ear is the mosquito when it has an intensity of 6.0x10-9 W/m2? (b) What is the decibel level for one mosquito, 10 cm from your ear? (b) What is the decibel level for two mosquitoes 10 cm away from your ear? (.10 m, 37.7 dB, 40.7 dB)

Electrostatics:

  1. Draw the electric field around 2 electrons separated by a small distance.
  1. The distance, center to center, of two protons in a nucleus is 3.00 x 10-15 m. What is the electrostatic force between those two protons? (25.6 N)
  1. A Styrofoam ball covered with a conducting paint has a mass of 5.0x10-3 kg and has a charge on 4.0 mC. What electric field directed upward will produce an electric force on the ball that will balance its weight? (12.2 N/C)
  1. A charge has a value of 30.0 mC. What is the electric field 4.00 cm away from the charge? (1.69E11 N/C)
  1. If the distance from a negative 3C charge is tripled, the electric field changes by what factor? (1/9)
  1. An electron with a charge value of 1.6 x 10-19 C is moving in the presence of an electric field of 400 N/C. What force does the electron experience? (6.4x10-17N)
  1. A proton, initially at rest, is accelerated through an electric potential difference of 650 V. What is the potential energy of the proton? What is the speed of the proton? (1.04x10-16J, 3.53x105 m/s)

Electric Circuits:

  1. What potential difference in required to cause a 5.5 A current to flow through a resistance of 12.0 Ohms? (66 V)
  1. A 6.0 ohm and a 12 ohm resistor are connected in series to a 36 V battery. What power is dissipated by the 6.0 ohm resistor? (24 W)
  1. A 12 V battery is connected to a 120 Ohm resistor. (a)What is the current in the circuit? (b) What is the power of the light bulb? (0.10 A, 1.2W)
  1. Three resistors of 12, 12, and 6.0 Ohms are connected in parallel. A 12 V battery is connected to the combination. What is the current through the battery? (b) What is the current through the 6.0 Ohm resistor? (4A, 2A)

Magnetism:

  1. A proton moves horizontally to the right in a magnetic field of 0.25 T directed vertically down with a speed of 1.8x107m/s. Find the force on the proton. (1.4x10-11N horizontally North )
  1. A wire that is 1.50 m long and carrying a current of 10.0 A horizontally South is in a uniform magnetic field. The force acting on the wire is 0.60 N directed up, out of the page. What is the strength of the magnetic field and in what direction is it pointing? (0.040 T East)
  1. A beam of electrons moves from the bottom of the page to the top of the page with a velocity of 2.5x106 m/s. If the electron’s move through a magnetic field of 6.0x10-2 T directed right to left, what is the force (# & direction) on one single electron? (2.4x10-14 N into the page; neg charge)
  1. A 2.5 m long wire is moved perpendicularly through a magnetic field of 0.73 T with a velocity of 15 m/s. If this wire is connected into a circuit with a resistance of 10.0 , what is the current in the circuit? (2.7 A)
  1. A solenoid 25.7 cm long is wound with 3500 turns of wire. What magnetic field is produced at the center of the solenoid when a current of 12.0 A flows? (0.205 T)
  1. An AC generator that delivers a peak voltage of 202 V connects to an electric heater with a resistance of 480. ohms. What is the effective current in the heater? (0.298 A)
  1. A step down transformer is used on a 4000 V line to provide a potential difference of 120 V. If the primary has 500 turns, how many turns must the secondary have? (15 turns)