Answer:
|Δf| = 37.3 kHz
Explanation:
given,
peak velocity = 4 m/s
speed of the sound = 1500 m/s
frequency = 7 MHz




= 37.3 kHz
|Δf| = 37.3 kHz
hence, frequency shift between the opening and closing valve is 37.3 kHz
Answer:
the wagon should be used as frame of reference if an observer said the child was not moving.
Explanation:
The state of motion of a body depends upon the frame of reference. It is the set of co-ordinates according to which the motion is analyzed. If a child is riding in a wagon, then he will be considered in motion to a person standing outside the wagon. Hence, if we take a frame of reference outside the wagon then the child must be in motion with respect to the observer. On the other hand if the observer is inside the wagon, then the child must be in rest with respect to the observer. Hence, if we take the wagon to be the frame of reference, then the child will be at rest with respect to the observer.
<u>Therefore, the wagon should be used as frame of reference if an observer said the child was not moving.</u>
The final answer is -322, 320 Joules. The solution for the problem is:
The equation that must be used in this problem is:
U = mCp(Tf-Ti)
where:
U = energy released or absorbed in Joules
m = mass in kg
Cp = specific heat of material in J/kg-C
Tf = final temperature, C
Ti = initial temperature, C
Looking up the Cp of granite gives a value of 790 J/kg-C.
U = 17kg (790 J/kg-C) (21-45)
<span>U = - 322, 320 Joules (negative means heat is released)</span>
<span>The angular momentum L of a rotating wheel with mass m, radius r, moment of inertia I, angular velocity ω, and velocity v of its outer edge:
</span><span>C) Iω</span>
To develop this problem it is necessary to apply the concepts related to the uni-axial deflection of bodies.
From the expression of Hooke's law we have to

Where,
E= Young's modulus
The strain
And substituting P/A for stress and
for strain gives that

Where,
P = Force
A = Area
L = Length
Therefore this can be re-arranged to give

If we want to calculate the deformation per unit area then we can also rewrite the equation as

Replacing with our values we have to


Therefore the posion ratio would be



Therefore the Poisson's ratio for this material is 0.4238