Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

1. (4 pts.) A wave on a string is described by: y 8 cos(2T(8x -10t)). Lengths ar

ID: 1776316 • Letter: 1

Question

1. (4 pts.) A wave on a string is described by: y 8 cos(2T(8x -10t)). Lengths are measured in meters and time in seconds. What is this wave's: Amplitude:m Wavelength: dt de, m Frequency Speed m/s in direction (circle one): X X +Y yY direction A ball of mass 25 g is moving east at a speed of 40 m/s, collides with a stationary ball of mass of 40 g. How much momentum and kinetic energy does the system have before the collision? 2. ' 02S, 40 system 1035 a. If they collide inelastically, what is the final speed of the 40 g ball? Vr %-2.5 What is the final momentum of the system? i. system at is the final kinetic energy of the system? KEsystem- b. If they collide elastically, what is the final speed of the 40 g ball? 06S i. What is the final momentum of the system? system ii. What is the final kinetic energy of the system? KE,ystem .

Explanation / Answer


1) y = 8*cos(2pi(8x-10t))


general form is y = A*cos(kx-wt)


amplitude is A = 8 m

wave number is k = (2*pi)/lamda

2*pi*8 = 2*pi/lamda

lamda = 1/8 =0.125 m is the wavelength

frequency is f = w/(2*pi)

w = 2*pi*10 = 2*pi*f


f = 10 Hz is the frequency

speed is v = w/k = (2*pi*10)/(2*pi*8) = 10/8= 1.25 m/s

direction is along +X