C a Search Collin College My Cour Question Completion Status

C a Search Collin College My Cour Question Completion Status: QUESTION 20 A fish tank has dimensions 36 cm wide by 1.0 m long by 0.60 m high. If the filter should process all the water in the tank once every 4.0 h, what should the flow speed be in the 3.0-cm-diameter input tube for the filter? O a. 0.07 m/s Ob, 0.02 m/s c. 0.10 m/s d. 76.39 m/s QUESTION 21 2 points An elastic cord is 65 cm long when a weight of 75 N hangs from it but is 85 cm long when a weight of 180 N hangs from it. What is the \"spring\" constant k of this elastic cord? a-525 N/m o b. 525 N/m c. 5.25 N/m d.-5.25 N/m

Solution

20

Flow speed = Volume/(Area*time)

Q = V/(A*t) = 0.36*1*0.6/(pi*0.015^2*4*60*60) = 0.0212 m/sec

Correct option is B.

32.

wavelength format is

y(x, t) = A*sin ((2*pi/lambda)x + (2*pi*f)t)

Comparing this to given equation:

2*pi/lambda = 5.6

lambda = 2*pi/5.6 = 1.1 m

Similarly

2*pi*f = 34

f = 34/(2*pi) = 5.4 Hz

Amplitude

A = 0.22 m/sec

Vmax = A*w = 0.22*34 = 7.48 m/sec

Vmin = 0 m/sec

So the correct option is B.