Two loudspeakers 42.0 m apart and facing each other emit identical 115 Hz sinusoidal sound waves in a room where the sound speed
is 345 m/s. Susan is walking along a line between the speakers. As she walks, she finds herself moving through loud and quiet spots. ?
1 answer:
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<h2>Complete Question:</h2>
You are on an aluminum ladder that is standing on the ground, trying to fix an electrical connection with a metal screwdriver having a metal handle. Your body is wet because you are sweating from the exertion; therefore, it has a resistance of 1.60 kΩ .
(a) If you accidentally touch the "hot" wire connected to the 120 V line, how much current will pass through your body?
(b) How much electrical power is delivered to your body?
<h2>Answer:</h2>(a) 0.075A
(b) 9W
<h2>Explanation:</h2>The voltage (V) passing across or supplied to a body is directly proportional to the current (I) flowing through the body as stated by Ohm's law. i.e
V ∝ I
=> V = I x R ----------------------(i)
Where;
R = constant of proportionality called resistance of the body
(a) As stated in the question;
The body is wet and thus will conduct electricity and has the following;
V = voltage supplied = 120V
R = resistance of the wet body = 1.60kΩ = 1.6 x 1000Ω = 1600Ω
Substitute these values into equation(i) as follows;
120 = I x 1600
Solve for I;
I =
I = 0.075A
Therefore the amount of current that will pass through your body is 0.075A
(b) Electrical power(P), which is commonly measured in Watts(W), delivered to a body is the product of the current(I) and voltage (V) supplied to the body. i.e
P = I x V ---------------------(ii)
Where;
I = 0.075A [as calculated above]
V = 120V [given in the question]
Substitute these values into equation (ii) as follows;
P = 0.075 x 120
P = 9W
Therefore, the electric power delivered to your body is 9W
Answer:
maximum amplitude = 0.13 m
Explanation:
Given that
Time period T= 0.74 s
acceleration of gravity g= 10 m/s²
We know that time period of simple harmonic motion given as
ω = 8.48 rad/s
ω=angular frequency
Lets take amplitude = A
The maximum acceleration given as
a= ω² A
The maximum acceleration should be equal to g ,then block does not separate
a= ω² A
10= 8.48² A
A=0.13 m
maximum amplitude = 0.13 m
Answer:
a) W=2.425kJ
b)
c)
d) Q=-2.425kJ
Explanation:
a)
First of all, we need to do a drawing of what the system looks like, this will help us visualize the problem better and take the best possible approach. (see attached picture)
The problem states that this will be an ideal system. This is, there will be no friction loss and all the work done by the object is transferred to the water. Therefore, we need to calculate the work done by the object when falling those 10m. Work done is calculated by using the following formula:
Where:
W=work done [J]
F= force applied [N]
d= distance [m]
In this case since it will be a vertical movement, the force is calculated like this:
F=mg
and the distance will be the height
d=h
so the formula gets the following shape:
so now e can substitute:
which yields:
W=2.425kJ
b) Since all the work is tansferred to the water, then the increase in internal energy will be the same as the work done by the object, so:
c) In order to find the final temperature of the water after all the energy has been transferred we can make use of the following formula:
Where:
Q= heat transferred
m=mass
=specific heat
= Final temperature.
= initial temperature.
So we can solve the forula for the final temperature so we get:
So now we can substitute the data we know:
Which yields:
d)
For part d, we know that the amount of heat to be removed for the water to reach its original temperature is the same amount of energy you inputed with the difference that since the energy is being removed this means that it will be negative.
