Physics Properties Of Matter Level: Misc Level
Identicle spheres are suspended by light strings. If air is blown between the spheres, the spheres will---.
a. move toward one another b. move away from one another c. stay the same distance from one another
Physics Heat & Thermodynamics Level: Misc Level
An immersion heater has a power rating of 900 watts. it is used to heat water for coffee. how many minutes are required to heat 11.98 liters of water from room temp (20 degrees celcius) to 90 celcius?
Physics Kinematics Level: Misc Level
Two rocks are thrown from the top of a very tall tower One of them is thrown horizontally to the left with an initial velocity of V left = 16.2 m/s. the other rock is thrown horizontally to the right with an initail velocity of V right =14.0 m /s how far will the rocks be from each other after 5.99 s? (neglect air resistance and assume that the rocks will not hit the ground within the time period of the question) in m )
e. 1.81* 10^2 f. 2.26* 10^2 g. 2.83* 10 ^2 h. 3.53* 10^2
Physics Waves And Oscillations Level: Misc Level
A tuning fork with a frequency of 440 Hz is held above a resonance tube that is partially filled with water. Assuming that the speed of sound in air is 342 m /s, for what three smallest heights of the air column will resonance occur? Where will the nodes and antinodes occur? (Hint: For resonance to occur, the frequency of the tuning fork must match that of the tube.)
Physics Waves And Oscillations Level: Misc Level
Bats emit sounds of frequencies around 35.0 kHz and use echolocation to find their prey. If a bat is moving at the speed of 12.0 m /s toward an insect at an air temperature of 20.0 % C,( assume the insect and air are still)
(a)What frequency is heard by the insect?
(b)What frequency is heard by the bat from the reflected sound?
(c)Would the speed of the bat affect the answers?
Physics Waves And Oscillations Level: Misc Level
Two point -source loudspeakers are a certain distance apart, and a person stands 12.0 m in front of one of them on a line perpendicular to the baseline of the speakers. If the speakers emit identical 1000.0 -Hz tones, what is their minimum nonzero separation so that the observer hears little or no sound? (Take the speed to be exactly 340 m/s.)
Physics Waves And Oscillations Level: Misc Level
Sound propagating through air at 30 % C passes through vertical cold front into air that is 4.0 % C.If the sound has a frequency of 2400 Hz, by what percentage does its wavelength change in crossing the boundary?
Physics Waves And Oscillations Level: Misc Level
The size of your eardrum (the tympanum) partially determines the upper frequency limit of your audible region, usually between 16,000 Hz and 20,000 Hz. If the wavelength is about twice the diameter of the eardrum and the air temperature is 20 % C, how wide is your eardrum? Is your answer reasonable?
Physics Properties Of Matter Level: Misc Level
Brass is an alloy of copper and zine. Does the addition of zine to copper cause an increase or decrease in the speed of sound in brass rods compared to copper rods? Explain.
Physics Waves And Oscillations Level: Misc Level
Particles approximately 3.0 x 10 -2 cm in diameter are to be scrubbed loose from machine parts in an aqueous ultrasonic cleaning bath. Above what frequency should the bath be operated to produce wavelengths of this size and smaller?
Physics Work,Power & Energy Level: Misc Level
A 0.75- kilogram sphere is released from rest and is moving 5.0 m /s after falling 2.0 meter in a viscous medium. How much work is done by the viscous force on the block?
(a)-6.1 Joules
(b)-4.6 Joules
(c)-5.3 Joules
(d)-6.8 Joules
(e)-2.7 Joules
Physics Force & Laws Of Motion Level: Misc Level
A 2.0 kilogram block sliding on a horizontal frictionless surface is attached to one end of a horizontal spring (k=200 N /m which has its other end fixed.If the block has a speed of 4.0 m /s as it passes through the equilibrium position, what is its speed when it is 20 centimeters from the equilibrium position?
(a)3.6 m/s
(b)3.1 m/s
(c)3.5 m/s
(d)1.9 m/s
(e)2.3 m/s
Physics Kinematics Level: Misc Level
A 1.2 - kilogram mass is projected from ground level with a velocity of 30 m/s at some unknown angle above the horizontal.A short time later, after being projected, the mass barely clears a 16- meter tall fence. Disregard air resistance and assume the ground is level. What is the kinetic energy of the mass as it clears the fence?
(a)0.35 kJ
(b)0.73 kJ
(c)0.40 kJ
(d)0.68 kJ
(e)0.19 kJ
Physics Rotational Mechanics Level: Misc Level
A pendulum is made by letting a 2.0 kilogram object swing at the end of a string that has a length of 1.5 meters. The maximum angle the string makes with the vertical as the pendulum swings is 30 degree.What is the speed of the object as it goes through the lowest point in its trajectory?
(a) 2.0 m /s
(b) 2.2 m /s
(c)2.5 m /s
(d)2.7 m /s
(e)3.1 m/s
Physics Work,Power & Energy Level: Misc Level
A 331 kg piano is being lifted at a steady speed from ground level straight up to an apartment 14.6 m above the ground. The crane that is doing the lifting produces a steady power of 361 W. How much time does it take to lift the piano?
