Answer:
Top 10 Residential Uses for Solar Energy.
01. Solar Powered Ventilation Fans.
02. Solar Heating for Your Swimming Pool.
03. Solar Water Heater.
04. Solar House Heating.
05.Solar Powered Pumps.
06. Charging Batteries With Solar Power.
07. Power Your Home With Photo-Electric.
08. Solar Energy For Cooking.
09. Solar energy for outdoor lighting.
10. Solar transportation.
Answer:
B
Explanation:
Density is about how closely compact molecules are. (^-^)
Answer:
a) ![\frac{F}{w} =2.347\times 10^{-6}\ N](https://tex.z-dn.net/?f=%5Cfrac%7BF%7D%7Bw%7D%20%3D2.347%5Ctimes%2010%5E%7B-6%7D%5C%20N)
b)
parallel to the earth surface.
- In this case according to the Fleming's left hand rule the direction of movement of bee must be in a direction parallel to the earth surface and perpendicular to the electric field at the same time.
Explanation:
Given:
mass of the bee, ![m=10^{-4}\ kg](https://tex.z-dn.net/?f=m%3D10%5E%7B-4%7D%5C%20kg)
charge acquired by the bee, ![q_2=23\times 10^{-12}\ C](https://tex.z-dn.net/?f=q_2%3D23%5Ctimes%2010%5E%7B-12%7D%5C%20C)
a.
Electrical field near the earth surface, ![E=100\ N.C^{-1}](https://tex.z-dn.net/?f=E%3D100%5C%20N.C%5E%7B-1%7D)
Now the electric force on the bee:
we know:
![F=\frac{1}{4\pi.\epsilon_0} \times \frac{q_1.q_2}{r^2}](https://tex.z-dn.net/?f=F%3D%5Cfrac%7B1%7D%7B4%5Cpi.%5Cepsilon_0%7D%20%5Ctimes%20%5Cfrac%7Bq_1.q_2%7D%7Br%5E2%7D)
![F=E.q_2](https://tex.z-dn.net/?f=F%3DE.q_2)
![F=100\times 23\times 10^{-12}](https://tex.z-dn.net/?f=F%3D100%5Ctimes%2023%5Ctimes%2010%5E%7B-12%7D)
![F=23\times 10^{-10}\ N](https://tex.z-dn.net/?f=F%3D23%5Ctimes%2010%5E%7B-10%7D%5C%20N)
The weight of the bee:
![w=m.g](https://tex.z-dn.net/?f=w%3Dm.g)
![w=10^{-4}\times 9.8](https://tex.z-dn.net/?f=w%3D10%5E%7B-4%7D%5Ctimes%209.8)
![w=9.8\times10^{-4}\ N](https://tex.z-dn.net/?f=w%3D9.8%5Ctimes10%5E%7B-4%7D%5C%20N)
Therefore the ratio :
![\frac{F}{w} =\frac{23\times 10^{-10}}{9.8\times10^{-4}}](https://tex.z-dn.net/?f=%5Cfrac%7BF%7D%7Bw%7D%20%3D%5Cfrac%7B23%5Ctimes%2010%5E%7B-10%7D%7D%7B9.8%5Ctimes10%5E%7B-4%7D%7D)
![\frac{F}{w} =2.347\times 10^{-6}\ N](https://tex.z-dn.net/?f=%5Cfrac%7BF%7D%7Bw%7D%20%3D2.347%5Ctimes%2010%5E%7B-6%7D%5C%20N)
b.
The condition for the bee to hang is its weight must get balanced by the electric force acing equally in the opposite direction.
So,
![F=9.8\times10^{-4}\ N](https://tex.z-dn.net/?f=F%3D9.8%5Ctimes10%5E%7B-4%7D%5C%20N)
![E.q_2=9.8\times10^{-4}\ N](https://tex.z-dn.net/?f=E.q_2%3D9.8%5Ctimes10%5E%7B-4%7D%5C%20N)
![E\times 23\times 10^{-12}=9.8\times10^{-4}\ N](https://tex.z-dn.net/?f=E%5Ctimes%2023%5Ctimes%2010%5E%7B-12%7D%3D9.8%5Ctimes10%5E%7B-4%7D%5C%20N)
parallel to the earth surface.
- In this case according to the Fleming's left hand rule the direction of movement of bee must be in a direction parallel to the earth surface and perpendicular to the electric field at the same time.
The minimum speed of the water must be 3.4 m/s
Explanation:
There are two forces acting on the water in the pail when it is at the top of its circular motion:
- The force of gravity, mg, acting downward (where m is the mass of the water and g the acceleration of gravity)
- The normal reaction, N also acting downward
Since the water is in circular motion, the net force must be equal to the centripetal force, so:
![N+mg=m\frac{v^2}{r}](https://tex.z-dn.net/?f=N%2Bmg%3Dm%5Cfrac%7Bv%5E2%7D%7Br%7D)
Where:
![g=9.8 m/s^2](https://tex.z-dn.net/?f=g%3D9.8%20m%2Fs%5E2)
v is the speed of the pail
r = 1.2 m is the radius of the circle
The water starts to spill out when the normal reaction of the pail becomes zero:
N = 0
When this occurs, the equation becomes:
![mg=m\frac{v^2}{r}\\v=\sqrt{gr}](https://tex.z-dn.net/?f=mg%3Dm%5Cfrac%7Bv%5E2%7D%7Br%7D%5C%5Cv%3D%5Csqrt%7Bgr%7D)
And substitutin the values of g and r, we find the minimum speed that the water must have in order not to spill out:
![v=\sqrt{(9.8)(1.2)}=3.4 m/s](https://tex.z-dn.net/?f=v%3D%5Csqrt%7B%289.8%29%281.2%29%7D%3D3.4%20m%2Fs)
Learn more about circular motion:
brainly.com/question/2562955
brainly.com/question/6372960
#LearnwithBrainly
If the boat is i travling at 10 m/s and the river is 8.0 m/s the boats speed is 18.0 m/s