I think it because of UV rays ultra violet ray which can make their colors different
Answer:
It should be option B polarization
Answer:
a)![\omega_1=8.168\,rad.s^{-1}](https://tex.z-dn.net/?f=%5Comega_1%3D8.168%5C%2Crad.s%5E%7B-1%7D)
b)![n_1=7.735 \,rev](https://tex.z-dn.net/?f=n_1%3D7.735%20%5C%2Crev)
c)![\alpha_1 =0.6864\,rad.s^{-2}](https://tex.z-dn.net/?f=%5Calpha_1%20%3D0.6864%5C%2Crad.s%5E%7B-2%7D)
d)![\alpha_2=4.1454\,rad.s^{-2}](https://tex.z-dn.net/?f=%5Calpha_2%3D4.1454%5C%2Crad.s%5E%7B-2%7D)
e)![t_2=1.061\,s](https://tex.z-dn.net/?f=t_2%3D1.061%5C%2Cs)
Explanation:
Given that:
- initial speed of turntable,
![N_0=0\,rpm\Rightarrow \omega_0=0\,rad.s^{-1}](https://tex.z-dn.net/?f=N_0%3D0%5C%2Crpm%5CRightarrow%20%5Comega_0%3D0%5C%2Crad.s%5E%7B-1%7D)
- full speed of rotation,
![N_1=78 \,rpm\Rightarrow \omega_1=\frac{78\times 2\pi}{60}=8.168\,rad.s^{-1}](https://tex.z-dn.net/?f=N_1%3D78%20%5C%2Crpm%5CRightarrow%20%5Comega_1%3D%5Cfrac%7B78%5Ctimes%202%5Cpi%7D%7B60%7D%3D8.168%5C%2Crad.s%5E%7B-1%7D)
- time taken to reach full speed from rest,
![t_1=11.9\,s](https://tex.z-dn.net/?f=t_1%3D11.9%5C%2Cs)
- final speed after the change,
![N_2=120\,rpm\Rightarrow \omega_2=\frac{120\times 2\pi}{60}=12.5664\,rad.s^{-1}](https://tex.z-dn.net/?f=N_2%3D120%5C%2Crpm%5CRightarrow%20%5Comega_2%3D%5Cfrac%7B120%5Ctimes%202%5Cpi%7D%7B60%7D%3D12.5664%5C%2Crad.s%5E%7B-1%7D)
- no. of revolutions made to reach the new final speed,
![n_2=11\,rev](https://tex.z-dn.net/?f=n_2%3D11%5C%2Crev)
(a)
∵ 1 rev = 2π radians
∴ angular speed ω:
![\omega=\frac{2\pi.N}{60}\, rad.s^{-1}](https://tex.z-dn.net/?f=%5Comega%3D%5Cfrac%7B2%5Cpi.N%7D%7B60%7D%5C%2C%20rad.s%5E%7B-1%7D)
where N = angular speed in rpm.
putting the respective values from case 1 we've
![\omega_1=\frac{2\pi\times 78}{60}\, rad.s^{-1}](https://tex.z-dn.net/?f=%5Comega_1%3D%5Cfrac%7B2%5Cpi%5Ctimes%2078%7D%7B60%7D%5C%2C%20rad.s%5E%7B-1%7D)
![\omega_1=8.168\,rad.s^{-1}](https://tex.z-dn.net/?f=%5Comega_1%3D8.168%5C%2Crad.s%5E%7B-1%7D)
(c)
using the equation of motion:
![\omega_1=\omega_0+\alpha . t_1](https://tex.z-dn.net/?f=%5Comega_1%3D%5Comega_0%2B%5Calpha%20.%20t_1)
here α is the angular acceleration
![78=0+\alpha_1\times 11.9](https://tex.z-dn.net/?f=78%3D0%2B%5Calpha_1%5Ctimes%2011.9)
![\alpha_1 = \frac{8.168 }{11.9}](https://tex.z-dn.net/?f=%5Calpha_1%20%3D%20%5Cfrac%7B8.168%20%7D%7B11.9%7D)
![\alpha_1 =0.6864\,rad.s^{-2}](https://tex.z-dn.net/?f=%5Calpha_1%20%3D0.6864%5C%2Crad.s%5E%7B-2%7D)
(b)
using the equation of motion:
![\omega_1\,^2=\omega_0\,^2+2.\alpha_1 .n_1](https://tex.z-dn.net/?f=%5Comega_1%5C%2C%5E2%3D%5Comega_0%5C%2C%5E2%2B2.%5Calpha_1%20.n_1)
![8.168^2=0^2+2\times 0.6864\times n_1](https://tex.z-dn.net/?f=8.168%5E2%3D0%5E2%2B2%5Ctimes%200.6864%5Ctimes%20n_1)
![n_1=48.6003\,rad](https://tex.z-dn.net/?f=n_1%3D48.6003%5C%2Crad)
![n_1=\frac{48.6003}{2\pi}](https://tex.z-dn.net/?f=n_1%3D%5Cfrac%7B48.6003%7D%7B2%5Cpi%7D)
![n_1=7.735\, rev](https://tex.z-dn.net/?f=n_1%3D7.735%5C%2C%20rev)
(d)
using equation of motion:
![\omega_2\,^2=\omega_1\,^2+2.\alpha_2 .n_2](https://tex.z-dn.net/?f=%5Comega_2%5C%2C%5E2%3D%5Comega_1%5C%2C%5E2%2B2.%5Calpha_2%20.n_2)
![12.5664^2=8.168^2+2\alpha_2\times 11](https://tex.z-dn.net/?f=12.5664%5E2%3D8.168%5E2%2B2%5Calpha_2%5Ctimes%2011)
![\alpha_2=4.1454\,rad.s^{-2}](https://tex.z-dn.net/?f=%5Calpha_2%3D4.1454%5C%2Crad.s%5E%7B-2%7D)
(e)
using the equation of motion:
![\omega_2=\omega_1+\alpha_2 . t_2](https://tex.z-dn.net/?f=%5Comega_2%3D%5Comega_1%2B%5Calpha_2%20.%20t_2)
![12.5664=8.168+4.1454\times t_2](https://tex.z-dn.net/?f=12.5664%3D8.168%2B4.1454%5Ctimes%20t_2)
![t_2=1.061\,s](https://tex.z-dn.net/?f=t_2%3D1.061%5C%2Cs)