Answer:
The force on q₁ due to q₂ is (0.00973i + 0.02798j) N
Explanation:
F₂₁ = ![\frac{K|q_1|q_2|}{r^2}.\frac{r_2_1}{|r_2_1|}](https://tex.z-dn.net/?f=%5Cfrac%7BK%7Cq_1%7Cq_2%7C%7D%7Br%5E2%7D.%5Cfrac%7Br_2_1%7D%7B%7Cr_2_1%7C%7D)
Where;
F₂₁ is the vector force on q₁ due to q₂
K is the coulomb's constant = 8.99 X 10⁹ Nm²/C²
r₂₁ is the unit vector
|r₂₁| is the magnitude of the unit vector
|q₁| is the absolute charge on point charge one
|q₂| is the absolute charge on point charge two
r₂₁ = [(9-5)i +(7.4-(-4))j] = (4i + 11.5j)
|r₂₁| = ![\sqrt{(4^2)+(11.5^2)} = \sqrt{148.25}](https://tex.z-dn.net/?f=%5Csqrt%7B%284%5E2%29%2B%2811.5%5E2%29%7D%20%3D%20%5Csqrt%7B148.25%7D)
(|r₂₁|)² = 148.25
![F_2_1=\frac{K|q_1|q_2|}{r^2}.\frac{r_2_1}{|r_2_1|} = \frac{8.99X10^9(14X10^{-6})(60X10^{-6})}{148.25}.\frac{(4i + 11.5j)}{\sqrt{148.25} }](https://tex.z-dn.net/?f=F_2_1%3D%5Cfrac%7BK%7Cq_1%7Cq_2%7C%7D%7Br%5E2%7D.%5Cfrac%7Br_2_1%7D%7B%7Cr_2_1%7C%7D%20%3D%20%5Cfrac%7B8.99X10%5E9%2814X10%5E%7B-6%7D%29%2860X10%5E%7B-6%7D%29%7D%7B148.25%7D.%5Cfrac%7B%284i%20%2B%2011.5j%29%7D%7B%5Csqrt%7B148.25%7D%20%7D)
= 0.050938(0.19107i + 0.54933j) N
= (0.00973i + 0.02798j) N
Therefore, the force on q₁ due to q₂ is (0.00973i + 0.02798j) N
Answer:
the frequency of the second harmonic of the pipe is 425 Hz
Explanation:
Given;
length of the open pipe, L = 0.8 m
velocity of sound, v = 340 m/s
The wavelength of the second harmonic is calculated as follows;
L = A ---> N + N--->N + N--->A
where;
L is the length of the pipe in the second harmonic
A represents antinode of the wave
N represents the node of the wave
![L = \frac{\lambda}{4} + \frac{\lambda}{2} + \frac{\lambda}{4} \\\\L = \lambda](https://tex.z-dn.net/?f=L%20%3D%20%5Cfrac%7B%5Clambda%7D%7B4%7D%20%2B%20%5Cfrac%7B%5Clambda%7D%7B2%7D%20%2B%20%5Cfrac%7B%5Clambda%7D%7B4%7D%20%5C%5C%5C%5CL%20%3D%20%5Clambda)
The frequency is calculated as follows;
![F_1 = \frac{V}{\lambda} = \frac{340}{0.8} = 425 \ Hz](https://tex.z-dn.net/?f=F_1%20%3D%20%5Cfrac%7BV%7D%7B%5Clambda%7D%20%3D%20%5Cfrac%7B340%7D%7B0.8%7D%20%3D%20425%20%5C%20Hz)
Therefore, the frequency of the second harmonic of the pipe is 425 Hz.
Work needed: 720 J
Explanation:
The work needed to stretch a spring is equal to the elastic potential energy stored in the spring when it is stretched, which is given by
![E=\frac{1}{2}kx^2](https://tex.z-dn.net/?f=E%3D%5Cfrac%7B1%7D%7B2%7Dkx%5E2)
where
k is the spring constant
x is the stretching of the spring from the equilibrium position
In this problem, we have
E = 90 J (work done to stretch the spring)
x = 0.2 m (stretching)
Therefore, the spring constant is
![k=\frac{2E}{x^2}=\frac{2(90)}{(0.2)^2}=4500 N/m](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2E%7D%7Bx%5E2%7D%3D%5Cfrac%7B2%2890%29%7D%7B%280.2%29%5E2%7D%3D4500%20N%2Fm)
Now we can find what is the work done to stretch the spring by an additional 0.4 m, that means to a total displacement of
x = 0.2 + 0.4 = 0.6 m
Substituting,
![E'=\frac{1}{2}kx^2=\frac{1}{2}(4500)(0.6)^2=810 J](https://tex.z-dn.net/?f=E%27%3D%5Cfrac%7B1%7D%7B2%7Dkx%5E2%3D%5Cfrac%7B1%7D%7B2%7D%284500%29%280.6%29%5E2%3D810%20J)
Therefore, the additional work needed is
![\Delta E=E'-E=810-90=720 J](https://tex.z-dn.net/?f=%5CDelta%20E%3DE%27-E%3D810-90%3D720%20J)
Learn more about work:
brainly.com/question/6763771
brainly.com/question/6443626
#LearnwithBrainly
If you are given distance and a period of time, you can calculate
the speed. The velocity of an object is the rate of change of its position with
respect to a frame of reference, and is a function of time. Velocity is
equivalent to a specification of its speed and direction of motion (e.g. 60
km/h to the north).