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A push or pull on an object is called force. Force can make stationary body in motion and moving body in rest.
Contact forces are those that result when the two interacting objects are perceived to be physically contacting each other.
Example: Frictional forces, tensional forces, normal forces, air resistance forces, and applied forces.
S.I. unit of force is Newton.
One Newton is a force required to push a body of mass of one kg to a distance of one meter.
In a game of tugof war, two teams pull the rope in opposite direction. The team that pulls the rope toward itself will become winner.
The total force acting perpendicular on a given surface is called thrust. Thrust acting upon a unit area is called pressure.
A water tank has four taps fixed at points A, B, C, D as shown in Fig. 11.4. The water will flow out at the same pressure from taps at
In the given water tank, B and C are at the same levels. Hence, from taps B and C, water will flow out at the same pressure.
The net force on an object is __________ if the two forces acting on it in opposite directions are equal.
The force on an object is zero if the two forces acting on it in opposite directions are equal in magnitude. This kind of force is called balanced force.
A force of 16N acts on an area of 50 cm^{2}. What is the pressure in pascal?
F = 16 N,
A = 50 cm^{2 }= 50 / 10000 m^{2}
We know that, P = F / A
∴ P = (16 x 10000) / 50 = 3200 Pa
A force applied on an object may change its speed.
If the force applied on the object is in the direction of its motion, the speed of the object increases.
If the force applied on the object is in the direction opposite to the direction of motion, the speed of the object decreases.
A force of 1200 N acts on the surface of an area 10 cm^{2} normally. What would be the thrust and pressure on the surface?
Force, F = 1200 N
Area, A = 10 cm^{2} = 10×10^{4} m^{2} = 10^{3} m^{2}
Thrust (perpendicular force), F = 1200 N
Pressure, P = F/A = 1200/10^{−3 }= 1.2×10^{6} N/m^{2}
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85 videos355 docs218 tests
