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Answers
Answer:
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a) Increased friction
b) Increased friction
c) Reduced friction
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A) Fossil fuel is a term used to describe a group of energy sources that were formed when ancient plants and organisms were subject to intense heat and pressure over millions of years.
Examples. Coal, Petroleum and Natural Gas.
B) Exhaustible resources, or non-renewable energy sources, are those that are limited and will run out. Examples of these are coal and petroleum.
Inexhaustible resources, or renewable resources, are those that will never run out as they aren't limited.Examples of these are wind and sun.
Explanation:
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a)Soles of shoes and tyres of vehicles have grooves because grooves allow small items such as sand or mud or water some place to move away sooner, allowing the surface to regain contact with the ground or street sooner as it slides.
b) Sportsmen use shoes with spikes because these shoes give them a better grip with the field while running. This is because the force of friction between the shoes and the ground increases with the help of spikes as they either pierce the ground if its wet and soft or produce a surface friction with the ground.
c) Ball bearings are used between hub and axle of fans and bicycles because ball bearings reduce friction and help in usage of ceiling fan and bicycles and prevent overheating due to friction.
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