Answer: The simplest form of ratio 6:15=2×3:5×3=2:5
Step-by-step explanation: So, 2:5 is equivalent to 6:15.
Answer:
Required total charge is 
coulombs per square meter.
Step-by-step explanation:
Given electric charge is dristributed over the disk,
so that the charge density at (x,y) is,
To find total charge on the disk let Q be the total charge and 
so that,
where A is the surface of disk.
![=\frac{2}{3}\int_{0}^{2\pi}(\sin\theta+\cos\theta)\Big[r^3\Big]_{0}^{4}d\theta+2\int_{0}^{2\pi}\Big[\frac{r^4}{4}\Big]d\theta](https://tex.z-dn.net/?f=%3D%5Cfrac%7B2%7D%7B3%7D%5Cint_%7B0%7D%5E%7B2%5Cpi%7D%28%5Csin%5Ctheta%2B%5Ccos%5Ctheta%29%5CBig%5Br%5E3%5CBig%5D_%7B0%7D%5E%7B4%7Dd%5Ctheta%2B2%5Cint_%7B0%7D%5E%7B2%5Cpi%7D%5CBig%5B%5Cfrac%7Br%5E4%7D%7B4%7D%5CBig%5Dd%5Ctheta)
![=\frac{128}{3}\Big[\sin\theta-\cos\theta\Big]_{0}^{2\pi}+128\times 2\pi](https://tex.z-dn.net/?f=%3D%5Cfrac%7B128%7D%7B3%7D%5CBig%5B%5Csin%5Ctheta-%5Ccos%5Ctheta%5CBig%5D_%7B0%7D%5E%7B2%5Cpi%7D%2B128%5Ctimes%202%5Cpi)
![=\frac{128}{3}\Big[\sin 2\pi-\cos 2\pi-\sin 0+\cos 0\Big]+256\pi](https://tex.z-dn.net/?f=%3D%5Cfrac%7B128%7D%7B3%7D%5CBig%5B%5Csin%202%5Cpi-%5Ccos%202%5Cpi-%5Csin%200%2B%5Ccos%200%5CBig%5D%2B256%5Cpi)
Hence total charge is coulombs per square meter.
Johnny ate 8 pies in 5 minutes
He must have ate 1 pie in (5/8) minutes
(5/8) minutes = 5/8 * 60 = 75/2 = 37.5 seconds
On each pie he spent 37.5 seconds.
