You and Tim, who is larger than you, are outside with a wagon. Tim (the bigger person) gets in the wagon and you (the smaller one) pull it. As you pull it, you accelerate until you reach a comfortable velocity. Then you stop and switch places with Tim. Tim now pulls you in the wagon, accelerating from a stop to a comfortable velocity. Now, Tim may be bigger than you, but you have been working out and are just as strong as Tim, so the force that Tim uses to pull the wagon is the same force that you used. You both pull with the exact same amount of force. Who was riding in the wagon when it had the greatest acceleration during start up? Why? Use Newton’s second law to explain. Now Sara comes along, and she is the exact same size as you. However, she is even stronger than you! When she pulls you in the wagon, she pulls with a greater force than when you pull her. Now who is in the wagon when it has the greatest acceleration? Explain, using Newton’s second law.

Follow these directions and answer the questions. 1. set up the ripple tank as in previous investigations. 2. bend the rubber tube to form a "concave mirror" and place in the ripple tank. the water level must be below the top of the hose. 3. generate a few straight pulses with the dowel and observe the reflected waves. do the waves focus (come together) upon reflection? can you locate the place where the waves meet? 4. touch the water surface where the waves converged. what happens to the reflected wave? 5. move your finger twice that distance from the hose (2f = c of c, center of the curvature) and touch the water again. does the image (the reflected wave) appear in the same location (c of c)? you may have to experiment before you find the exact location. sometimes it is hard to visualize with the ripple tank because the waves move so quickly. likewise, it is impossible to "see" light waves because they have such small wavelengths and move at the speed of light. however, both are examples of transverse waves and behave in the same way when a parallel wave fronts hit a curved surface.

Two technicians are discussing a resistance measurement between the can-h and can-l wires. technician a says this measurement should be done with the ignition switch in the "run" position. technician b states that a measurement of 0 ohms indicates an open in the network. which technician is correct?

Two 1.20-m nonconducting wires meet at a right angle. one segment carries + 2.50 µc of charge distributed uniformly along its length, and the other carries - 2.50 µc distributed uniformly along it, as shown in fig. 21.50. ( a. find the magnitude and direction of the electric field these wires produce at point p, which is 60.0 cm from each wire. ( b. if an electron is released at p, what are the magnitude and direction of the net force that these wires exert on it?