1.) Two dams form artificial lakes of equal depth. However, one lake backs up 15 km behind the dam, and the other backs up 30 km behind. What effect does the difference in length have on the pressures on the dams?
a) The pressure from the shorter lake will be 1/2 that of the longer lake.
b) The pressurew from the shorter lake will be 1/4 that of the longer lake.
c) The pressure from the two will be the same.
d) The pressure from the longer lake will be 1/2 that of the shorter lake.
e) The pressure difference will depend on the actual depths.
2.) An ice cube floats in a glass of water. As the ice melts, the level of the water in the glass will:
a) Increase b) Decrease c) Stay the same.
3.) If the distance to a source is halved, how will the sound intensity level change?
a) Increase by a factor of 2.
b)Increase by a factor of 4.
c) Increase by 3 dB.
d) Increase by 6 dB.
e) depends on the acutal distance.
4.) Consider two slabs of material with the same thickness, but made of materials differing in their index of refraction. Which of the following are true?
a) Light incident at an angle from the normal will reflect off the two slabs are different angles.
b) Light incident normally will refract at different angles in the two slabs.
c) The speed of light will differ in the two slabs.
d) The frequency of light will differ in the two slabs.
e) The wavelength of light will be the same in the two slabs.
5.) Concrete is sold by the cubic yard. What is the mass, in kilograms, of one cubic yard of concrete that is five times as dense as water? (1.000 m = 1.094 yd, and 1.000 m ) of water has a mass of 1.000 x 10 kg.)
a) 764 kg b) 6546 kg c) 3819 kg d) 8733 kg e) 2420 kg
6.) A piece of iron sinks to the bottom of a lake where the pressure is 21 atm. Which statement best describes what happens to the density of that piece of iron?
a) Its density decreases slightly.
b)Its density increases slightly.
c) Its density becomes 21 times greater.
d) There has been no change in the density of the iron.