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Questions in physics

📝 Answered - The loudness, [tex]$L$[/tex], measured in decibels (Db), of a sound intensity, [tex]$I$[/tex], measured in watts per square meter, is defined as [tex]$L-10 \log \frac{1}{I_0}$[/tex], where [tex]$10-10^{-12}$[/tex] and is the least intense sound a human ear can hear. What is the approximate loudness of a rock concert with a sound intensity of [tex]$10^{-1}$[/tex]? A. 2 Db B. 22 Db C. 60 Db D. 110 Db

📝 Answered - Warm tools, wires, or other equipment could be a sign of too much: A. Voltage fault circuit-interrupter B. Current C. Resistance D. Electricity

📝 Answered - The loudness, [tex]$L$[/tex], measured in decibels (Db), of a sound intensity, [tex]$I$[/tex], measured in watts per square meter, is defined as [tex]$L=10 \log \frac{l}{l_0}$[/tex], where [tex]$l_0=10^{-12}$[/tex] and is the least intense sound a human ear can hear. What is the approximate loudness of a rock concert with a sound intensity of [tex]$10^{-1}$[/tex]?

📝 Answered - You find yourself in a situation with reduced visibility due to fog. There is a car 100m in front of you. Which lights can you use? A. Indicators. B. Fog lights. C. Headlights. D. High beams. Hint: You must select ALL correct answers.

📝 Answered - In observing an oxygen emission line from a warm gas cloud that is expected to appear at 500 nm, the line is seen at 525 nm instead (5% longer). Which of the following is true? A. The observed emission line indicates that a chemical change has occurred. B. The object is moving toward the observer at 5% of the speed of light. C. The object is moving away from the observer at 5% of the speed of light. D. The observer's equipment is inaccurate since emission lines do not change. E. The velocity of the light is greater than expected.

📝 Answered - Planet X has a moon similar to Earth's moon. Which path would this moon's orbit take? If, for some reason, the planet is destroyed and no longer exists, which path would the moon take?

📝 Answered - Which of the following statements about scientific models is not true? A. Scientific models can save money and lives. B. Scientific models allow scientists to test their predictions. C. Scientific models allow scientists to study systems that no longer exist. D. Scientific models are used rarely.

📝 Answered - How does the intensity of a sound wave change if the distance from the source is reduced by a factor of 3? A. The intensity increases by a factor of 9. B. The intensity decreases by a factor of 9. C. The intensity decreases by a factor of 3. D. The intensity increases by a factor of 3.

📝 Answered - An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?

📝 Answered - An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?