Factors affecting friction
The intensity of friction depends on following factors: i) The area involved in friction. ii) The pressure applied on the surfaces. Force = Pressure ´ Area Frictional force will increase, if the area of contact will increase or if pressure applied on the surface increased.
Methods to reduce friction
i) Polish the contact surface. ii) Put oil or grease so that it fills in the small gaps of the flat parts. iii) Use ball bearings to reduce area of contact between rotating parts.
Lubrication
Following methods can be used to reduce friction: Oil is either thin or viscous. It depends upon SAE No. of oil. (SAE means Society of Automotive Engineers). If we use very viscous oil, it does not reach all the parts. Very thin oil will flows away easily and gets wasted. Grease is used in such cases. It is generally used around ball-bearing. Normal grease or oil is never used where there is high pressure, high temperature and high speed. Special lubricants are used in such cases. In cold season the oil becomes thick and in hot season it becomes thin. Therefore selection of lubrication also depends on the season. It is always advisable to refer operating manual of the equipment before selecting the lubricant.
Answer: Well you didn't give any answers so my guess would be it depends how much force you put into it and where you throw it.
Explanation:
Answer:
B. temperature of the objects
C. The Densities are equal.
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What is density?</h3>
Density is mass per unit volume or mass of a unit volume of a material substance.
If m1, V1 and D1 = mass, volume and density respectively of ball C
m2, V2 and D2 = mass, volume and density respectively of ball D
According to the Question ,
Therefore,
Hence, D1 = D2
Learn more about density here:brainly.com/question/15164682
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Explanation:
a)Snell's law states that when light travels from a rarer to a denser substance, like air to water or from a less dense layer of the atmosphere to a denser layer, it bends towards the normal{an imaginary line that is perpendicular to the surface of both media}. However,the opposite occurs when light moves from a more dense to a less dense medium. The angle between the normal and the refracted light ray is known as the angle of refraction.
In case of earth as light from the stars enters the earth atmosphere it bends towards smaller angle because the earth density increases as the light travel towards the earth troposphere from the exosphere as per the Snell's law described above.
b)Light rays that travel straight down do not bend, while rays that enter the Earth's atmosphere at a shallower angle get refracted and bend towards the normal, roughly following the direction of the Earth's curvature.
This means that celestial objects in the zenith position directly above you appear in the correct position, while objects closer to the horizon appear to be higher up in the sky than they actually are.
