Answer:
![q=1.95*10^{-7}C](https://tex.z-dn.net/?f=q%3D1.95%2A10%5E%7B-7%7DC)
Explanation:
According to the free-body diagram of the system, we have:
![\sum F_y: Tcos(15^\circ)-mg=0(1)\\\sum F_x: Tsin(15^\circ)-F_e=0(2)](https://tex.z-dn.net/?f=%5Csum%20F_y%3A%20Tcos%2815%5E%5Ccirc%29-mg%3D0%281%29%5C%5C%5Csum%20F_x%3A%20Tsin%2815%5E%5Ccirc%29-F_e%3D0%282%29)
So, we can solve for T from (1):
![T=\frac{mg}{cos(15^\circ)}(3)](https://tex.z-dn.net/?f=T%3D%5Cfrac%7Bmg%7D%7Bcos%2815%5E%5Ccirc%29%7D%283%29)
Replacing (3) in (2):
![(\frac{mg}{cos(15^\circ)})sin(15^\circ)=F_e](https://tex.z-dn.net/?f=%28%5Cfrac%7Bmg%7D%7Bcos%2815%5E%5Ccirc%29%7D%29sin%2815%5E%5Ccirc%29%3DF_e)
The electric force (
) is given by the Coulomb's law. Recall that the charge q is the same in both spheres:
![(\frac{mg}{cos(15^\circ)})sin(15^\circ)=\frac{kq^2}{r^2}(4)](https://tex.z-dn.net/?f=%28%5Cfrac%7Bmg%7D%7Bcos%2815%5E%5Ccirc%29%7D%29sin%2815%5E%5Ccirc%29%3D%5Cfrac%7Bkq%5E2%7D%7Br%5E2%7D%284%29)
According to pythagoras theorem, the distance of separation (r) of the spheres are given by:
![sin(15^\circ)=\frac{\frac{r}{2}}{L}\\r=2Lsin(15^\circ)(5)](https://tex.z-dn.net/?f=sin%2815%5E%5Ccirc%29%3D%5Cfrac%7B%5Cfrac%7Br%7D%7B2%7D%7D%7BL%7D%5C%5Cr%3D2Lsin%2815%5E%5Ccirc%29%285%29)
Finally, we replace (5) in (4) and solving for q:
![mgtan(15^\circ)=\frac{kq^2}{(2Lsin(15^\circ))^2}\\q=\sqrt{\frac{mgtan(15^\circ)(2Lsin(15^\circ))^2}{k}}\\q=\sqrt{\frac{10*10^{-3}kg(9.8\frac{m}{s^2})tan(15^\circ)(2(0.22m)sin(15^\circ))^2}{8.98*10^{9}\frac{N\cdot m^2}{C^2}}}\\q=1.95*10^{-7}C](https://tex.z-dn.net/?f=mgtan%2815%5E%5Ccirc%29%3D%5Cfrac%7Bkq%5E2%7D%7B%282Lsin%2815%5E%5Ccirc%29%29%5E2%7D%5C%5Cq%3D%5Csqrt%7B%5Cfrac%7Bmgtan%2815%5E%5Ccirc%29%282Lsin%2815%5E%5Ccirc%29%29%5E2%7D%7Bk%7D%7D%5C%5Cq%3D%5Csqrt%7B%5Cfrac%7B10%2A10%5E%7B-3%7Dkg%289.8%5Cfrac%7Bm%7D%7Bs%5E2%7D%29tan%2815%5E%5Ccirc%29%282%280.22m%29sin%2815%5E%5Ccirc%29%29%5E2%7D%7B8.98%2A10%5E%7B9%7D%5Cfrac%7BN%5Ccdot%20m%5E2%7D%7BC%5E2%7D%7D%7D%5C%5Cq%3D1.95%2A10%5E%7B-7%7DC)
Answer:
The maximum height the box will reach is 1.72 m
Explanation:
F = k·x
Where
F = Force of the spring
k = The spring constant = 300 N/m
x = Spring compression or stretch = 0.15 m
Therefore the force, F of the spring = 300 N/m×0.15 m = 45 N
Mass of box = 0.2 kg
Work, W, done by the spring =
and the kinetic energy gained by the box is given by KE = ![\frac{1}{2} mv^2](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%20mv%5E2)
Since work done by the spring = kinetic energy gained by the box we have
=
therefore we have v =
=
=
= 5.81 m/s
Therefore the maximum height is given by
v² = 2·g·h or h =
=
= 1.72 m
Objects are known to go down because of a unbalanced force
Answer:
10 years
Explanation:
As you can understand from the question it is given that the planet is already filled to half of its capacity. Also the population doubles in 10 years. To fill up the planet completely the population needs to double only once. To do that only 10 years are required.
As it is mentioned there are no other factors affecting the growth rate, in 10years the planet will be filled to its carrying capacity.