Mac and Keena are experimenting with pulses on a rope. Mac vibrates one end up and down while Keena holds the other end. This creates a pulse which they observe moving from end to end. How does the position of a point on the rope before the start of the pulse compare to its position after the pulse passes? Explain your reasoning.
Answer: 1000 Hz
Explanation:
You can calculate frequency by dividing velocity by wavelength
Frequency = velocity/wavelength
Find velocity first.
900 m/3 s = 300 m/s
Plug values in to find frequency.
F = (300 m/s)/0.3 m
F = 1000 Hz
Answer:
The width of the central bright fringe on the screen is observed to be unchanged is 
Explanation:
To solve the problem it is necessary to apply the concepts related to interference from two sources. Destructive interference produces the dark fringes. Dark fringes in the diffraction pattern of a single slit are found at angles θ for which
Where,
w = width
wavelength
m is an integer, m = 1, 2, 3...
We here know that as 
as w are constant, then
We need to find 
, then
Replacing with our values:
Therefore the width of the central bright fringe on the screen is observed to be unchanged is
Using the equation v(average)=x traveled/time
v = 100/2.5
You get 40 kilometers per hour
Hope this helped!
Answer: 249 seconds
Explanation:
Speed of bike = 2.52 m/s
Distance = 628 m
Time taken = ? ( let the unknown value be Z)
Recall that speed is the distance covered per unit time.
Hence, speed = Distance / Time taken
Time taken = Distance / speed
Z = 628m / 2.52 m/s
Z = 249.2 seconds (Round to nearest tenth i.e 249 seconds)
Thus, it takes 249 seconds for the girl to get to her friends house
