A sound wave enters the thin tube at P and exits at Q. Assume r = 0.41m and the wavelength is 1.86m. What is the smallest length d that results in destructive interference at Q?

More force is required to pull the plug in a full bathtub than when it is empty. Does this contradict Archimedes' principle? Explain your answer.

A 2.00-kg object hangs, at rest, on a 1.00-m-long string attached to the ceiling. A 100-g object is fired with a speed of 20 m/s at the 2.00-kg object, and the two objects collide and stick together in a totally inelastic collision. Write an equation for the motion of the system after the collision. Assume air resistance is negligible.

Consider a thought experiment. You place an expanded balloon of air on weighing scales outside in the early morning. The balloon stays on the scales and you are able to measure changes in its mass. Does the mass of the balloon change as the day progresses? Discuss the difficulties in carrying out this experiment.

(Indicates a review question, which means it requires only a basic understanding of the material to answer. Questions without this designation typically require integrating or extending the concepts presented thus far.) A wind is blowing from the north (the air is moving toward the south). When a person is walking toward the north, is the relative speed of the wind that the person senses greater than, the same as, or less than the speed the person senses when not walking? How about when the person is walking toward the south?

Scientists and engineers must interpret problems from various sources. We can practice this skill anytime we read a newspaper or magazine or browse the Internet. Consider the Rocket Car urban legend that can be found on many Internet sites, in which the Arizona Highway Patrol allegedly found the vaporized wreckage of an automobile. The story goes that after some analysis and investigation, it was believed that a former Air Force Sergeant attached solid-fuel rockets to his 1967 Chevy Impala and ignited the rockets approximately 3.9 miles from the crash site. The vehicle quickly reached a speed of approximately 275 mph. It continued at this speed for 20 to 25 seconds. The car remained on the highway for 2.6 miles before the driver applied the brakes. The brakes melted and the tires blew out, causing the vehicle to become airborne. It traveled through the air for 1.3 miles before it hit a cliff face 125 feet above the road. Of course, this story was debunked. It is physically implausible, but it can still provide an opportunity to practice analyzing a problem. a. C Draw a Sketch of the Situation. b. C For the constant-velocity part of the cars motion, identify initial and final positions, the velocity, and the time interval. c. N Calculate the displacement using the position data and then again using the velocity and time data. Are your results consistent? d. C If your results are not consistent, reread the legend and identify possible sources of the discrepancy.

You are on the Pirates of the Caribbean attraction in the Magic kingdom at Disney World. Your boat rules through a pirate battle, in which cannons on a ship and in a fort are firing at each other. While you are aware that the splashes in the water do not represent actual cannonballs, you begin to wonder about such battles in the days of the pirates. Suppose the fort and the ship are separated by 75.0 m. You sec that the cannons in the fort are aimed so that their cannonballs would be fired horizontally from a height of 7.00 m above the water. (a) You wonder at what speed they must be fired in order to hit the ship before falling in the water. (b) Then, you think about the sludge that must build up inside the barrel of a cannon. This sludge should slow down the cannonballs. A question occurs in your mind: if the cannonballs can be fired at only 50.0% of the speed found earlier, is it possible to fire them upward at some angle to the horizontal so that they would reach the ship?

Find the order of magnitude of the number of table- tennis halls (hat would ill into a typical-size room (without being crushed).

(Indicates a review question, which means it requires only a basic understanding of the material to answer. Questions without this designation typically require integrating or extending the concepts presented thus far.) . Jane and John are both on roller skates and facing each other, First Jane pushes John with her hands and they move apart. They get together again, and John pushes Jane equally hard with his hands and they move apart Is their subsequent motion any different in the two cases? Why or why not?

. In January 2003, an 18-year-old student gained a bit of fame for surviving—with only minor injuries—a remarkable traffic accident. The vehicle he was driving was "clipped" by another one, left the road, and rolled several times. He was thrown upward from the vehicle (he wasn't wearing a seat belt) and ended up dangling from an overhead telephone cable and a ground wire about 8 meters above the ground. Rescuers got him down after 20 minutes. It is estimated that he reached a maximum height of about 10 meters. (a) Estimate the driver's vertical speed when he was thrown from the vehicle. (b) If he had not landed in the wires, how fast would he have been going when he hit the ground?