~1~
Block A weighs 1.40 N, and block B weighs 4.20 N. The coefficient of kinetic friction between all surfaces is 0.30. Find the magnitude of the horizontal force necessary to drag block B to the left at constant speed if A and B are connected by a light, flexible cord passing around a fixed, frictionless pulley.
Two loudspeakers, A and B, are driven by the same amplifier and emit sinusoidal waves in phase. Speaker B is 2.00 m to the right of speaker A. Consider point Q along the extension of the line connecting the speakers, 1.00 m to the right of speaker B. Both speakers emit sound waves that travel directly from the speaker to point Q. The speed of sound is 343 m/s. (a) What is the lowest frequency for which constructive interference occurs at point Q?
~2b~
Two loudspeakers, A and B, are driven by the same amplifier and emit sinusoidal waves in phase. Speaker B is 2.00 m to the right of speaker A. Consider point Q along the extension of the line connecting the speakers, 1.00 m to the right of speaker B. Both speakers emit sound waves that travel directly from the speaker to point Q. The speed of sound is 343 m/s. (b) What is the lowest frequency for which destructive interference occurs at point Q?
~3a~
Suppose that the rod in the figure is made of copper (for copper, k = 385 W/m∙K), is 45.0 cm long, and has a cross-sectional area of 1.25 cm2. Let TH = 100 °C and TC = 0.0 °C. (a) What is the final steady-state temperature gradient along the rod? Round your answer to three significant places.
~3b~
Suppose that the rod in the figure is made of copper (for copper, k = 385 W/m∙K), is 45.0 cm long, and has a cross-sectional area of 1.25 cm2. Let TH = 100 °C and TC = 0.0 °C. (b) At what rate does heat flow through this rod? Round your answer to three significant places.
~3c~
Suppose that the rod in the figure is made of copper (for copper, k = 385 W/m∙K), is 45.0 cm long, and has a cross-sectional area of 1.25 cm2. Let TH = 100 °C and TC = 0.0 °C. (c) What is the final steady-state temperature at a point in the rod 12.0 cm from its left end? Round your answer to three significant places.
~4~
Operation of an Inkjet Printer. In an inkjet printer, letters are built up by squirting drops of ink at the paper from a rapidly moving nozzle. The ink drops, which have a mass of 1.4 × 10-8g each, leave the nozzle and travel toward the paper at 20 m/s, passing through a charging unit that gives each drop a positive charge qby removing some electrons from it. The drops then pass between parallel deflecting plates 2.0 cm long where there is a uniform vertical electric field with magnitude 8.0 × 104 N/C. If a drop is to be deflected 0.30 mm by the time it reaches the end of the deflection plates, what magnitude of charge must be given to the drop? Round your answer to three significant places.
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