Yes for an object moving on a horizontal plane, R = mg (where mg = weight). therefore, for an object moving on a horizontal plane: F = μmg
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Answer:</h2>
<u>Friction:</u>
When an object slips on a surface, an opposing force acts between the tangent planes which acts in the opposite direction of motion. This opposing force is called Friction. Or in other words, Friction is the opposing force that opposes the motion between two surfaces.
The main component of friction are:
<u>Normal Reaction (R):
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Suppose a block is placed on a table in the above picture, which is in resting state, then two forces are acting on it at that time.
The first is due to its weight mg which is working from its center of gravity towards the vertical bottom.
The second one is superimposed vertically upwards by the table on the block, called the reaction force (P). This force passes through the center of gravity of the block.
Due to P = mg, the box is in equilibrium position on the table.
<u>Coefficient of friction ( </u>μ )<u>:
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The ratio of the force of friction and the reaction force is called the coefficient of friction.
Coefficient of friction, µ = force of friction / reaction force
μ = F / R
The coefficient of friction is volume less and dimensionless.
Its value is between 0 to 1.
<u>Advantage and disadvantage from friction force:
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- The advantage of the force of friction is that due to friction, we can walk on the earth without slipping.
- Brakes in all vehicles are due to the force of friction.
- We can write on the board only because of the force of friction.
- The disadvantage of this force is that due to friction, some parts of energy are lost in the machines and there is wear and tear on the machines.
<u>How to reduce friction:
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- Using lubricants (oil or grease) in machines.
- Friction can be reduced by using ball bearings etc.
- Using a soap solution and powder.
Answer:
The forces creating the net force must lie in the same direction.
Explanation:
newton's second law states that the net force acting on the body is equal to the product of mass and the acceleration of the body.
If there are several forces acting on the body in different directions, then we have to find teh net force by using the vector sum and then find the acceleration.
It is not necessary that all the forces acting in the same direction.
if they are in different directions then we have to find the net force by t=using the formula for the vector sum.
Answer:
A physical change involves a change in physical properties. Examples of physical properties include melting, transition to a gas, change of strength, change of durability, changes to crystal form, textural change, shape, size, color, volume and density.
Answer:

Explanation:
Initial angular speed of the ferris wheel is given as



final angular speed after friction is given as



now angular acceleration is given as



now torque due to friction on the wheel is given as



Now the power required to rotate it with initial given speed is

