Answer:
a)
, b)
, c)
.
Explanation:
a) Let assume that car travel on a horizontal surface. The equations of equilibrium of the car are:
![\Sigma F_{x} = F - \mu_{r}\cdot N = 0](https://tex.z-dn.net/?f=%5CSigma%20F_%7Bx%7D%20%3D%20F%20-%20%5Cmu_%7Br%7D%5Ccdot%20N%20%3D%200)
![\Sigma F_{y} = N - m\cdot g = 0](https://tex.z-dn.net/?f=%5CSigma%20F_%7By%7D%20%3D%20N%20-%20m%5Ccdot%20g%20%3D%200)
After some algebraic handling, the following expression for the propulsion force is constructed:
![F = \mu_{r}\cdot m \cdot g](https://tex.z-dn.net/?f=F%20%3D%20%5Cmu_%7Br%7D%5Ccdot%20m%20%5Ccdot%20g)
![F = (0.06)\cdot (1500\,kg)\cdot (9.807\,\frac{m}{s^{2}} )](https://tex.z-dn.net/?f=F%20%3D%20%280.06%29%5Ccdot%20%281500%5C%2Ckg%29%5Ccdot%20%289.807%5C%2C%5Cfrac%7Bm%7D%7Bs%5E%7B2%7D%7D%20%29)
![F = 882.63\,N](https://tex.z-dn.net/?f=F%20%3D%20882.63%5C%2CN)
b) The power require to move the car at a speed of 5 meters per second is:
![\dot W = F\cdot v](https://tex.z-dn.net/?f=%5Cdot%20W%20%3D%20F%5Ccdot%20v)
![\dot W = (882.63\,N)\cdot (5\,\frac{m}{s} )](https://tex.z-dn.net/?f=%5Cdot%20W%20%3D%20%28882.63%5C%2CN%29%5Ccdot%20%285%5C%2C%5Cfrac%7Bm%7D%7Bs%7D%20%29)
![\dot W= 4413.15\,W](https://tex.z-dn.net/?f=%5Cdot%20W%3D%204413.15%5C%2CW)
c) The efficiency of the car is:
![\eta = \frac{(882.63\,N)\cdot (15\,mi)\cdot (\frac{1609\,m}{1\,mi} )}{(1.4\times 10^{8}\,J)} \times 100\,\%](https://tex.z-dn.net/?f=%5Ceta%20%3D%20%5Cfrac%7B%28882.63%5C%2CN%29%5Ccdot%20%2815%5C%2Cmi%29%5Ccdot%20%28%5Cfrac%7B1609%5C%2Cm%7D%7B1%5C%2Cmi%7D%20%29%7D%7B%281.4%5Ctimes%2010%5E%7B8%7D%5C%2CJ%29%7D%20%5Ctimes%20100%5C%2C%5C%25)
![\eta = 15.216\,\%](https://tex.z-dn.net/?f=%5Ceta%20%3D%2015.216%5C%2C%5C%25)
Answer:
Beryllium
Beryllium is an alkaline metallic element that is highly toxic. It is known for its sugary sweet taste and some of its common uses are in X-rays and fluorescent lights.
Beryllium : A very thorough and technical site about this mineral.
Chromite
Chromite is the ore of chromium and is a very hard metal, and diamond is the only thing harder. This hardness is what allows a chrome finish to take a high polish.
Chromite : This site talks about its history and characteristics.
Cobalt
Cobalt is famous for the incredible blue color it imparts to glass and pigment. It has been found in meteorites and is used in invisible ink. It is a brittle metal and resembles iron.
Cobalt : This site has photos, video, charts and physical and atomic descriptions.
Columbite-tantalite
Columbite-tantalite group is a mineral used widely in technology. Electronics, automotive systems and health products like the pacemaker need this mineral to operate. It is mined in Africa and has earned the name of Coltan over the last few years.
Columbite-tantalite : Information about its role in the world under the name 'Coltan'.
Copper
Copper is a common metal throughout the world. It is used for currency, jewelry, plumbing and to conduct electricity. It is a soft, orange-red metal.
Copper : This site talks about its properties, uses and makeup.
Explanation:
Hope that helps :)
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Answer:
This process is known as static electricity
Explanation:
When balloon is rubbed on the wool , a negative charge is usually formed. When the balloon is then held over—but not touching—some bits of paper, some of the bits jump up to the balloon. The bits which jump up to the balloon are positive charged and we know that unlike charges attract.
This process explains static electricity which is when the charges on a material are not in a balanced state.
Answer:
11760 joules
Explanation:
Given
Mass (m) = 75kg
Height (h) = 16m
Required
Determine the increment in potential energy (PE)
This is calculated as thus:
PE = mgh
Where g = 9.8m/s²
Substitute values for m, g and h.
P.E = 75 * 9.8 * 16
P.E = 11760 joules