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Now that you've completed Chapter 2, it's time to try some dvat problems that are a bit more challenging than the run of the mill back-of-the-chapter problems. Here are two of them. We provide the complete problem statements here for reference. You'll enter your solutions in WebAssign E.2.6.

The Tardy Student

Refer to the overhead diagram above. A student who is late to class is running down the hallway with uniform acceleration. As he runs past a classroom with three doors, all three doors are wide open, and the AP Physics students just happen to have their stopwatches ready, since this student is late frequently. The student, running to the right, is shown in 3 successive positions: 1,2,3. The distance between doors is d and the width of each door is w. t = 0 is the time when the student is at position 1. The time for the student to run from position 1 to position 2 is t₁. The time to run from position 2 to position 3 is t₂. Determine the student's acceleration, a, in terms of d, w, t₁, and t₂. That is, you will end up with an equation that has acceleration on the left and an algebraic combination of the other 4 symbols on the right.

The Window Problem

Figure 1. Point of release of red and blue balls		Figure 2. Some time after blue ball was released

The graphics above are screen captures from this animation. A blue and a red ball are dropped from the roof of the historic Watts hospital (now a part of NCSSM). The red ball is released time T after the blue ball. The balls are initially height h above the top of the window as shown in Figure 1. The window is a square with side s. What must the time delay T be so that the blue and red balls reach the top and bottom of the window at the same instant of time? (Figure 2 shows a situation in which the red ball was released too late.) Give your result in terms of s, h, and g only.

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