Physics Test 3 Answers Flashcards
Why does a helium balloon rise?
The buoyant force from the air that the balloon displaces.
A uniform wooden block floats with 40% of its volume above the surface of the water. What is the mass density of the wood?
60% the density of the water is floating in
What happens as water flows from a narrow to wide place?
It slows down
At what temp do objects start to glow?
All objects glow with electromagnetic radiation. Warmer objects just glow with a higher frequency emissions.
Why does metal in oven burn your hand vs the heat of the air in the oven?
Metal conducts heat better than air
F=
F=1/T when T= period
If a vibrating string is made shorter, how is the frequency affected?
The frequency goes up
The reason a rubbed balloon attracts a wooden meter stick is
The balloon has a negative charge that leads to the polarization of molecules in the meter stick.
T or F in a gas with constant temp all the particles have the same KE
F
Bending of waves due to change in velocity is
refraction
If two tuning forks with slightly different frequencies are played at the same time, what is the fluctuations of the sounds called? What is the frequencies of the fluctuations?
Beats; I f1-f2 I where f1+f1 are the individual frequencies.
A stringed instrument vibrates and produces a sound. What are the same?
Frequency of vibration of the string and frequency of the sound.
Resonance occurs every
half a wavelength
When wavelength decreases frequency
increases
