For each labelled point, indicate whether constructive or destructive interference takes
place at that point.
A ride at the local amusement park is called "Standing on Standing Waves". Which position (a node or an antinode) on the ride would give the greatest thrill?
How many nodes and how many anti-nodes appear in the standing wave below?
For a standing wave on a string, you are given three statements:
you can have any
and any
as long as the relationship,
is satisfied.
only certain wavelengths and frequencies are allowed
the wave velocity is only dependent on the medium
Which of the statements are true:
A and C only
B and C only
A, B, and C
none of the above
Consider the diagram below of a standing wave on a string 9 m long that is tied at both ends. The wave velocity in the string is 16 m
s
. What is the wavelength?
Summary
A wave is formed when a continuous number of pulses are transmitted through a medium.
A peak is the highest point a particle in the medium rises to.
A trough is the lowest point a particle in the medium sinks to.
In a transverse wave, the particles move perpendicular to the motion of the wave.
The amplitude is the maximum distance from equilibrium position to a peak (or trough), or the maximum displacement of a particle in a wave from its position of rest.
The wavelength (
) is the distance between any two adjacent points on a wave that are in phase. It is measured in metres.
The period (
) of a wave is the time it takes a wavelength to pass a fixed point. It is measured in seconds (s).
The frequency (
) of a wave is how many waves pass a point in a second. It is measured in hertz (Hz) or
.
Frequency:
Period:
Speed:
or
.
When a wave is reflected from a fixed end, the resulting wave will move back through the medium, but will be inverted. When a wave is reflected from a free end, the waves are reflected, but not inverted.
Exercises
A standing wave is formed when:
a wave refracts due to changes in the properties of the medium
a wave reflects off a canyon wall and is heard shortly after it is formed
a wave refracts and reflects due to changes in the medium
two identical waves moving different directions along the same medium interfere
How many nodes and anti-nodes are shown in the diagram?
Draw a transverse wave that is reflected from a fixed end.
Draw a transverse wave that is reflected from a free end.
A wave travels along a string at a speed of
. If the frequency of the source of the wave is 7,5 Hz, calculate:
the wavelength of the wave
the period of the wave
Water waves crash against a seawall around the harbour. Eight waves hit the seawall in 5 s. The distance between successive troughs is 9 m. The height of the waveform trough to crest is 1,5 m.
How many complete waves are indicated in the sketch?
Write down the letters that indicate any TWO points that are:
Wayne and Dennis like to ride the bike path from Riverside Park to the beach. Dennis’s speed is seven miles per hour faster than Wayne’s speed, so it takes Wayne 2 hours to ride to the beach while it takes Dennis 1.5 hours for the ride. Find the speed of both bikers.
from theory: distance [miles] = speed [mph] × time [hours]
info #1
speed_Dennis × 1.5 = speed_Wayne × 2
=> speed_Wayne = 0.75 × speed_Dennis (i)
info #2
speed_Dennis = speed_Wayne + 7 [mph] (ii)
use (i) in (ii) => [...]
speed_Dennis = 28 mph
speed_Wayne = 21 mph
George
Let W be Wayne's speed in miles per hour and D be Dennis's speed in miles per hour. We know that W + 7 = D and W * 2 = D * 1.5.
Substituting the first equation into the second:
W * 2 = (W + 7) * 1.5
W * 2 = W * 1.5 + 7 * 1.5
0.5 * W = 7 * 1.5
W = 7 * 3 or 21
W is 21
D = W + 7
D = 21 + 7
D = 28
Salma
Devon is 32 32 years older than his son, Milan. The sum of both their ages is 54 54. Using the variables d d and m m to represent the ages of Devon and Milan, respectively, write a system of equations to describe this situation. Enter the equations below, separated by a comma.
please why is it that the 0is in the place of ten thousand
Grace
Send the example to me here and let me see
Stephen
A meditation garden is in the shape of a right triangle, with one leg 7 feet. The length of the hypotenuse is one more than the length of one of the other legs. Find the lengths of the hypotenuse and the other leg
however, may I ask you some questions about Algarba?
Amoon
hi
Enock
what the last part of the problem mean?
Roger
The Jones family took a 15 mile canoe ride down the Indian River in three hours. After lunch, the return trip back up the river took five hours. Find the rate, in mph, of the canoe in still water and the rate of the current.
Shakir works at a computer store. His weekly pay will be either a fixed amount, $925, or $500 plus 12% of his total sales. How much should his total sales be for his variable pay option to exceed the fixed amount of $925.
I'm guessing, but it's somewhere around $4335.00 I think
Lewis
12% of sales will need to exceed 925 - 500, or 425 to exceed fixed amount option. What amount of sales does that equal? 425 ÷ (12÷100) = 3541.67. So the answer is sales greater than 3541.67.
Check:
Sales = 3542
Commission 12%=425.04
Pay = 500 + 425.04 = 925.04.
925.04 > 925.00
Munster
difference between rational and irrational numbers
Jazmine trained for 3 hours on Saturday. She ran 8 miles and then biked 24 miles. Her biking speed is 4 mph faster than her running speed. What is her running speed?