Answer:
a = w² r
Explanation:
In this exercise, indicate that the wheel has angular velocity w, the worm experiences the same angular velocity if it does not move, and has an acceleration towards the center of the circle, according to Newton's second law, called the centripetal acceleration.
a = v² / r
angular and linear variables are related
v = w r
we substitute
a = w² r
where r is the radius of the wheel
Answer:
<h2>
96 Joules</h2>
Explanation:
We know that efficiency is the ratio of output power by input power. i.e. Efficiency describes the quality of machine or system how good it is.
Solution,
Energy input of system = 120 J
Efficiency = 80% = ![\frac{80}{100} = 0.8](https://tex.z-dn.net/?f=%20%5Cfrac%7B80%7D%7B100%7D%20%20%3D%200.8)
Now,
According to definition,
Efficiency = ![\frac{output}{input}](https://tex.z-dn.net/?f=%20%5Cfrac%7Boutput%7D%7Binput%7D%20)
Cross multiplication:
![output \: = \: 0.8 \times 120](https://tex.z-dn.net/?f=output%20%5C%3A%20%20%3D%20%20%5C%3A%200.8%20%5Ctimes%20120)
Calculate the product
![output \: = 96 \: joules](https://tex.z-dn.net/?f=output%20%5C%3A%20%20%3D%2096%20%5C%3A%20joules)
Hope this helps...
Good luck on your assignment...
This question involves the concepts of dynamic pressure, volume flow rate, and flow speed.
It will take "5.1 hours" to fill the pool.
First, we will use the formula for the dynamic pressure to find out the flow speed of water:
![P=\frac{1}{2}\rho v^2\\\\v=\sqrt{\frac{2P}{\rho}}](https://tex.z-dn.net/?f=P%3D%5Cfrac%7B1%7D%7B2%7D%5Crho%20v%5E2%5C%5C%5C%5Cv%3D%5Csqrt%7B%5Cfrac%7B2P%7D%7B%5Crho%7D%7D)
where,
v = flow speed = ?
P = Dynamic Pressure = 55 psi
= 379212 Pa
= density of water = 1000 kg/m³
Therefore,
![v=\sqrt{\frac{2(379212\ Pa)}{1000\ kg/m^3}}](https://tex.z-dn.net/?f=v%3D%5Csqrt%7B%5Cfrac%7B2%28379212%5C%20Pa%29%7D%7B1000%5C%20kg%2Fm%5E3%7D%7D)
v = 27.54 m/s
Now, we will use the formula for volume flow rate of water coming from the hose to find out the time taken by the pool to be filled:
![\frac{V}{t} = Av\\\\t =\frac{V}{Av}](https://tex.z-dn.net/?f=%5Cfrac%7BV%7D%7Bt%7D%20%3D%20Av%5C%5C%5C%5Ct%20%3D%5Cfrac%7BV%7D%7BAv%7D)
where,
t = time to fill the pool = ?
A = Area of the mouth of hose =
= 1.98 x 10⁻⁴ m²
V = Volume of the pool = (Area of pool)(depth of pool) = A(1.524 m)
V =
= 100.1 m³
Therefore,
![t = \frac{(100.1\ m^3)}{(1.98\ x\ 10^{-4}\ m^2)(27.54\ m/s)}\\\\](https://tex.z-dn.net/?f=t%20%3D%20%5Cfrac%7B%28100.1%5C%20m%5E3%29%7D%7B%281.98%5C%20x%5C%2010%5E%7B-4%7D%5C%20m%5E2%29%2827.54%5C%20m%2Fs%29%7D%5C%5C%5C%5C)
<u>t = 18353.5 s = 305.9 min = 5.1 hours</u>
Learn more about dynamic pressure here:
brainly.com/question/13155610?referrer=searchResults
Answer:
706.68 N
Explanation:
By Hooke's law,
![F = ke](https://tex.z-dn.net/?f=F%20%3D%20ke)
![k=\dfrac{F}{e}](https://tex.z-dn.net/?f=k%3D%5Cdfrac%7BF%7D%7Be%7D)
Using the values in the question,
![k=\dfrac{265\text{ N}}{0.15 \text{ m}}=1766.7\text{ N/m}](https://tex.z-dn.net/?f=k%3D%5Cdfrac%7B265%5Ctext%7B%20N%7D%7D%7B0.15%20%5Ctext%7B%20m%7D%7D%3D1766.7%5Ctext%7B%20N%2Fm%7D)
When e = 0.4 m,
![F = 1766.7\text{ N/m}\times0.4\text{ m}=706.68\text{ N}](https://tex.z-dn.net/?f=F%20%3D%201766.7%5Ctext%7B%20N%2Fm%7D%5Ctimes0.4%5Ctext%7B%20m%7D%3D706.68%5Ctext%7B%20N%7D)
Let the rescue boat starts at an angle theta with the North
now its velocity towards East is given as
![v_x = 24sin\theta](https://tex.z-dn.net/?f=v_x%20%3D%2024sin%5Ctheta)
![v_y = -24cos\theta + 3](https://tex.z-dn.net/?f=v_y%20%3D%20-24cos%5Ctheta%20%2B%203)
now in some time "t" it will catch the boy
so we will have
![t = \frac{0.5}{24sin\theta}](https://tex.z-dn.net/?f=t%20%3D%20%5Cfrac%7B0.5%7D%7B24sin%5Ctheta%7D)
also we have
![t = \frac{2}{-24cos\theta + 3}](https://tex.z-dn.net/?f=t%20%3D%20%5Cfrac%7B2%7D%7B-24cos%5Ctheta%20%2B%203%7D)
now we have
![\frac{2}{-24cos\theta + 3} = \frac{0.5}{24sin\theta}](https://tex.z-dn.net/?f=%5Cfrac%7B2%7D%7B-24cos%5Ctheta%20%2B%203%7D%20%3D%20%5Cfrac%7B0.5%7D%7B24sin%5Ctheta%7D)
![4*24sin\theta = - 24cos\theta + 3](https://tex.z-dn.net/?f=4%2A24sin%5Ctheta%20%3D%20-%2024cos%5Ctheta%20%2B%203)
![96 sin\theta + 24cos\theta = 3](https://tex.z-dn.net/?f=96%20sin%5Ctheta%20%2B%2024cos%5Ctheta%20%3D%203)
by solving above we got
![\theta = 164 degree](https://tex.z-dn.net/?f=%5Ctheta%20%3D%20164%20degree)