PHYSICS PLLZ HELP
posted by FRANK .
1- wave velocity is related to
a- period b-wavelength c-amplitude d-all of these
2- wave amplitude is related to
a- wave velocity b- frequency c- energy d-wave length
3-which of the following radiation has te smallest frequency?
a- infrared b- visible c- ultraviolet d-x-rays
4-light can travel to the earth from a distant star but sound cannot.why is it?
a- light is an electromagnetic wave and sound requires a medium
b- the sun does not make sound
c- light is a longitudinal wave and sound is a transverse wave
d-the statement is false both will travel in empty space
5- resonance occurs when
a- two different objects vibrate with different frequencies
b- two different objects produce beats
c- an object having certain natural frequency is set in vibration by second object vibrating at that frequency.
d- an object produces a sound.
6- when oscillator is driven in resonance,
a- there are no standing waves
b-all natural frequencies are present
c- there is maximum energy transfer
d- any driving frequency may be used.
7-imags of objects are formed by lenses because of
a- refraction b-diffraction c-internal reflectn d-all of these
8- complete destructive interference occurs for two waves of the same amplitude and frequency when the waves are out of phase by:
a- zero degree
b- 90 degrees
c- 180 degrees
9-what is the wavelength in meters of radio waves produced by a radio station with a frequency of 1400 KHz?
a- 2.1 X 10^7 m
b-2.1 X 10 ^12m
c- 4.23 X 10 ^14
d- 2.1 X 10^2m
10- what is the frequency in hertz of a sound wave( v=340 m/s) with wavelength of 0.20m?
a- 1.7 X 10^3 Hz
b- 17 X 10^3 Hz
c- 1.7 X 10^2
11- a series of ocean waves each 6.0m from crest to crest moving past an observer at a rate of 2.0 waves per second has what speed?
a-3 m/s b- 12 m/s c- 33 m/s d- 720 m/s
12- how many times greater is the speed of red light(700nm) than the speed of violet light(400nm) in a vacuum?
a- 1,100 nm b- 300 nm c- 175 times d- both have the same speed
13- how many times faster is the speed of light in vacuum than the speed of sound in air?
a- 10^6 times
b- 10^ -6 times
c- 300 X 10^6 times
d- 300 times
14- the speed of light in diamond is 1.24 X 10^8 m/s. what is the index of refraction of diamond?
a- 2.42 b-242 c- 0.41 d- 1.24
15- a particular material has an index of refraction of 1.25. what percent of the speed of light in vacuum is the speed of light in the material?
a- 125 %
c- 12.5 %
d- 80 %
16- an object is placed 8cm from a converging spherical lens. The general characteristics of the image for a lens with a focal length of f=12 cm.
a- real, inverted, and enlarged
b- virtual, upright, and enlarged
c- virtual, inverted and smaller
d- real , upright and smaller
17- a simple magnifying glass has a focal length of 6.0cm. an object is placed 4.0 cm from it. Give the characteristics of the image.
a- virtual, inverted and smaller
b- real, inverted and enlarged
c- virtual, upright and enlarged
d- real, upright and smaller
look it up on the internet duh
Frank -- we do not DO homework assignments or answer test questions.
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The "work function", or the minimum energy needed to eject an electron from the metal, can be expressed in several different ways. As stated on the applet page, sodium has a work function of 2.75 eV.