Question

1. Define pressure.
2. Write all the effects of force.
3. A force of 200N is applied to an object of area 4 m². Evaluate pressure.​

Answer 1

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Pressure:-

• Pressure is defined as force applied perpendicular to an unit area.

• Pressure is a scalar quantity.

• S.I unit of pressure is Pascal (Pa).

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Effects of force:-

Force can change shape of an object.

• When we pull a rubber band, it gets longer and longer. Once we stop the pull, it recoils into it's original state.

Force can change size on an object.

• When we apply force on an uneven object, it gets even.

Force can change direction of an object.

• Kicking the football in the opposite direction.

Force can change the speed of an object.

• When someone pulls a moving cycle from behind, it's speed gets reduced.

Force can change the momentum of an object from zero (to start) or to zero (to stop).

• We can start to move a football when we apply force on it. (from zero)

• And the same football once the goal keeper applies force in the opposite direction it stops. (to zero)

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Evaluate Pressure:-

• Force applied = 200 N

• Area = 4 m²

We know that,

$\boxed{\pink{\sf Pressure \: = \: \dfrac{F}{A}}}$

Substituting the values,

• $\sf Pressure \: = \: \dfrac{200}{4}$

• $\sf Pressure \: = \: \dfrac{\cancel{200}}{\cancel{4}}$

• $\sf Pressure \: = \: 50 \: Pa$

Therefore,

• Pressure = 50 Pa

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Answer 2

${\large{\bold{\rm{\underline{Question-1:}}}}}$

Define pressure.

Pressure is defined as force per unit area. It is also called as thrust.

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${\large{\bold{\rm{\underline{Question-2:}}}}}$

Write all the effects of force.

Force changes the direction of motion:

When a ball strikes any surface like wall, iit's motion gets changed in the opposite direction.

Force can change the state of the object:

When we push a table, the state of table changes from rest to motion.

Force changes the shape of object:

When we expand elastic band, the shape of the band changes.

Force changes the speed of object:

When we accelerate a car, it's speed increases. When we apply brake to the car, it's speed decreases.

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${\large{\bold{\rm{\underline{Question-3:}}}}}$

A force of 200N is applied to an object of area 4 m². Evaluate pressure.

${\large{\bold{\rm{\underline{Given:}}}}}$

★ Force = 200N

★ Area = 4 m²

${\large{\bold{\rm{\underline{To\:find:}}}}}$

★ Pressure applied.

${\large{\bold{\rm{\underline{Formulae\:applied:}}}}}$

★ P = F/A

Here,

• P = Pressure
• F = Force
• A = Area

${\large{\bold{\rm{\underline{Solution:}}}}}$

~ Let us apply the formula to find the pressure.

↝ P = F/A

↝ P = 200/4

↝ P = 50 pascal

Hence, the pressure applied is 50 Pa.

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