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.
Answers
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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,
Substituting the values,
Therefore,
- Pressure = 50 Pa
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Define pressure.
Pressure is defined as force per unit area. It is also called as thrust.
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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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A force of 200N is applied to an object of area 4 m². Evaluate pressure.
★ Force = 200N
★ Area = 4 m²
★ Pressure applied.
★ P = F/A
Here,
- P = Pressure
- F = Force
- A = Area
~ 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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