This is a symbolic version of 23. A girl of mass mG is standing on a plank of mass mP. Both are originally at rest on a frozen lake that constitutes a frictionless, flat surface. The girl begins to walk along the plank at a constant velocity vGP to the right relative to the plank. (The subscript GP denotes the girl relative to plank.) (a) What is the velocity vPI of the plank relative to the surface of the ice? (b) What is the girls velocity vGI relative to the ice surface?

Day 15 2/8/2016 Phys 5b HW #1 asked to calculate how long will it take for the displacement to decrease one percent to its original value, referring to the exponential envelope. Pretend as if the sinusoidal didn’t exist Reading: 15.2, 15.5, 15.7, 16.1, 16.2 Review: Standing Waves by adding up two waves of the same amplitude, wavelength, and frequency, but propagating in opposite direction, y 1, t) = Asin(kx wt) and y 2x, t) = Asin(kx + wt), we obtained a standing wave, and we have shown that its mode of vibration depend on the boundary conditions as follows Closed Closed Standing Wave Pattern λ = 2L n = 1, 2, 3, … n n P n