Download Homework Qs For Exam 3 | PHYS 140 - How Things Work and more Quizzes Classical Physics in PDF only on Docsity!
Pendulum A has a period of 2 seconds. Pendulum B is four times as long as pendulum A. What is the period of pendulum B? 4 seconds. the period for a pendulum = 2pie * squrt(length of pendulum/ acceleration due to g) TERM 2 A child is playing on a swing. As long as he does not swing too high the time it takes him to complete one full oscillation will DEFINITION 2 both the amplitude of the motion and the weight of the child. TERM 3 What is true for a pendulum oscillating with large amplitude? DEFINITION 3 The period depends on the amplitude of oscillation TERM 4 What provides the restoring force for the harmonic oscillator in a clock or watch which operates with a balance ring? DEFINITION 4 The coil spring TERM 5 One reason that quartz watches can be much more accurate compared with wind-up clocks is because DEFINITION 5 the piezoelectric crystal oscillates at a very high frequency
You have two springs hanging from the ceiling. Spring A is stiffer (higher spring constant) than spring B. You hang identical ma spring A The stiffer the spring, the shorter the period, the higher the frequency TERM 7 Each xylophone bar is actually a harmonic oscillator that vibrates when struck by a wooden mallet. When bending in its fundament DEFINITION 7 lower the pitch of the bar The more massive bar, the lower the pitch TERM 8 If you blow carefully across the top of a drinking straw, it will emit a tone. If you now close off the bottom of the straw with DEFINITION 8 go down by an octave-its frequency will decrease by a factor of 2 TERM 9 When you blow air across one of those ends, the air in that straw vibrates and the straw emits a tone-its fundamental pitch. If DEFINITION 9 decrease in pitch (shift to a lower frequency). increasing the mass of air in a column of air decreases the pitch that it can produce TERM 10 The strings of a guitar vibrate at different frequencies. They have different thicknesses because DEFINITION 10 a thicker, more massive string vibrates more slowly than a thinner string of the same length and tension.
The rear defroster of your car operates on a current of 5 A. If the voltage across it is 10 V, how much electric power is it con 50 watts voltage = (electrostatic pe)/ charge 10v = x/5A 50 watts = x TERM 17 When the flashlight is on, current flows through these objects, one after the next, over and over again. When you turn the switc DEFINITION 17 charges accumulate on either side of the open switch and repel any additional like charges that approach them from the bulb or battery. TERM 18 You have covered a grounded metal surface with a layer of photoconductor. Working in the dark, you sprinkle negative charge onto DEFINITION 18 the left half becomes neutral while the right half remains negatively charged. When light travels through a photoconductor it leaves the region neutral TERM 19 Two 1.5-V batteries placed in series end-to- end (both are polarized in the same direction) to power a flashlight. If the current DEFINITION 19 5.0 Ohms voltage drop = current * electrical resistance 1.
- 1.5 = 3v 3v = 1.5A * X 5.0 ohms = electrical resistance TERM 20 Your cat has chewed the cord to your desk lamp and has created a short circuit-an electric connection from one wire to the other DEFINITION 20 current will bypass the bulb and the bulb will not light up.
Inside the battery (we stress INSIDE the battery) in a closed circuit (consider the battery attached to a lightbulb with the lig positive charge from its negative terminal to its positive terminal. batteries use chemical forces to transfer charges from its - terminal to its + terminal TERM 22 The north pole of a permanent magnet is clinging to the front surface of your steel refrigerator. If you flip the permanent magn DEFINITION 22 place a north pole at its surface and attract the permanent magnet. TERM 23 Two permanent magnets can DEFINITION 23 attract or repel TERM 24 When you pick up paperclips with a magnet, you find that several paperclips can be held in a string, sticking to each other and DEFINITION 24 ferromagnetic materials. & composed of ferromagnetic domains that can be aligned with the magnet. TERM 25 what changes can you make to a bar magnets polarization? DEFINITION 25
- get rid of it altogether 2. switch its north and south poles
an electric field wave oscillates north and south, and the wave is travelling straight up, then what direction does the magnetic east and west TERM 32 why can an electromagnetic wave not exist if it only has an electrical field and no magnetic field? DEFINITION 32 an electromagnetic wave must have a magnetic field that changes with time to produce its electric field. TERM 33 An FM radio station instructs your radio receiver how to move its speaker cone by varying the DEFINITION 33 frequency of the radio wave it produces. TERM 34 Why does FM radio sound richer than AM radio? DEFINITION 34 FM has a larger bandwidth.
