Answer:
![\frac{dV}{dt} = 0.453 Volts/s](https://tex.z-dn.net/?f=%5Cfrac%7BdV%7D%7Bdt%7D%20%3D%200.453%20Volts%2Fs)
Explanation:
As we know that two resistors are in parallel
so we have
![V = i R](https://tex.z-dn.net/?f=V%20%3D%20i%20R)
where we know that
![\frac{1}{R} = \frac{1}{R_1} + \frac{1}{R_2}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7BR%7D%20%3D%20%5Cfrac%7B1%7D%7BR_1%7D%20%2B%20%5Cfrac%7B1%7D%7BR_2%7D)
so we have
![\frac{1}{V} = \frac{1}{i}(\frac{1}{R_1} + \frac{1}{R_2})](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7BV%7D%20%3D%20%5Cfrac%7B1%7D%7Bi%7D%28%5Cfrac%7B1%7D%7BR_1%7D%20%2B%20%5Cfrac%7B1%7D%7BR_2%7D%29)
now to find the rate of change we have
![\frac{1}{V^2}\frac{dV}{dt} = \frac{1}{i^2}\frac{di}{dt}(\frac{1}{R_1} + \frac{1}{R_2}) + \frac{1}{i}(\frac{1}{R_1^2}(\frac{dR_1}{dt}) + \frac{1}{R_2^2}(\frac{dR_2}{dt}))](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7BV%5E2%7D%5Cfrac%7BdV%7D%7Bdt%7D%20%3D%20%5Cfrac%7B1%7D%7Bi%5E2%7D%5Cfrac%7Bdi%7D%7Bdt%7D%28%5Cfrac%7B1%7D%7BR_1%7D%20%2B%20%5Cfrac%7B1%7D%7BR_2%7D%29%20%2B%20%5Cfrac%7B1%7D%7Bi%7D%28%5Cfrac%7B1%7D%7BR_1%5E2%7D%28%5Cfrac%7BdR_1%7D%7Bdt%7D%29%20%2B%20%5Cfrac%7B1%7D%7BR_2%5E2%7D%28%5Cfrac%7BdR_2%7D%7Bdt%7D%29%29)
![\frac{1}{V} = \frac{1}{3}(\frac{1}{4} + \frac{1}{3})](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7BV%7D%20%3D%20%5Cfrac%7B1%7D%7B3%7D%28%5Cfrac%7B1%7D%7B4%7D%20%2B%20%5Cfrac%7B1%7D%7B3%7D%29)
![\frac{1}{V} = 0.194](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7BV%7D%20%3D%200.194)
now from above equation we have
![(0.194)^2\frac{dV}{dt} = \frac{1}{3^2}(0.02)(\frac{1}{4} + \frac{1}{3}) + \frac{1}{3}(\frac{1}{4^2}(0.4) + \frac{1}{3^2}(0.2))](https://tex.z-dn.net/?f=%280.194%29%5E2%5Cfrac%7BdV%7D%7Bdt%7D%20%3D%20%5Cfrac%7B1%7D%7B3%5E2%7D%280.02%29%28%5Cfrac%7B1%7D%7B4%7D%20%2B%20%5Cfrac%7B1%7D%7B3%7D%29%20%2B%20%5Cfrac%7B1%7D%7B3%7D%28%5Cfrac%7B1%7D%7B4%5E2%7D%280.4%29%20%2B%20%5Cfrac%7B1%7D%7B3%5E2%7D%280.2%29%29)
![0.0376\frac{dV}{dt} = 1.296\times 10^{-3} + 0.0157](https://tex.z-dn.net/?f=0.0376%5Cfrac%7BdV%7D%7Bdt%7D%20%3D%201.296%5Ctimes%2010%5E%7B-3%7D%20%2B%200.0157)
![\frac{dV}{dt} = 0.453 Volts/s](https://tex.z-dn.net/?f=%5Cfrac%7BdV%7D%7Bdt%7D%20%3D%200.453%20Volts%2Fs)
Answer:
486 of cell membranes
Explanation:
one cell membrane has 7*10^-9m as the height
So, by dividing 3.4 with 7*10^-9 you will get the number of cell require to form the height.
3.4/(7*10^-9)=485.71
because we can't have decimal number of cell we would round it into three significant figures, 486.
C) refract
Explanation:
When light passes from air into water, the light waves will bend or they refract and the pencil will appear to be broken.
In normal space, light travels along a straight path with no alteration of the path along which it travels.
- When light crosses the boundary from a denser to a less dense medium, it is refracted.
- Refraction implies that the angle of the light is bent.
- This is because the new medium causes the light rays to slow down compared to the speed it was coming forth with.
Learn more:
Refraction brainly.com/question/12370040
#learnwithBrainly
Explanation:
Tea cools faster in a cup than in a kettle because when it is on a cup it is more spread out so the cooler air around it is able to cool down each molecule faster than if it were in a kettle which is cooling down slower because the tea is not a spread out