Answer the following questions. Just the answer is fine no need to show your work.

1. A spring is underdamped with a damping constant of 1.5 kg/s. If a mass of 2.3 kg is attached to the spring and is set into simple harmonic motion, how long will it take the amplitude to be reduced to 25% of its original value? 0.88 s 4.3 s 2.1 s 0.77 s 2. Which of the following travelling waves has the lowest speed? D(x, t) = 15sin(2x - 5t) - D(x,t) = 7sin(4x - 2t) - D(x, t) 11sin(3x-3t) - D(x,t) = 9sin(x - 2t) 3. A standing wave is described by the equation y(x, t) 8.0 cos(2nt) sin(x). The standing wave formed when a traveling wave moving in the positive x-direction reflected off a fixed end and the reflected wave interfered with the incident wave. Which of the following equations could represent the incident wave? y(x,t) = 8.0sin(x 2Trt) - y(x,t) = 4.0sin(nx + 2Tre) Oy(x,t) = 4.0sin(x - 2Tre) - y(x,t) = 4.0sin(2x - Tre)