2. Force is a pull or a push on an object.
It is exerted when two objects interact with
each other.
It is equal in size but opposite in direction.
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3. Force is measured in newtons (N).
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𝐹 = 𝑚𝑎
Where F - force
m - mass of the object
a -acceleration
4. Hooke’s Law – larger the force applied
on a spring, the more it will extend.
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5. It is the net force.
It is zero when:
◦ the object is stationary.
◦ the object moves at a constant speed.
It is not zero when the object accelerates or
decelerates.
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6. Also called Torque.
It is the turning effect of force acting
on a body about an axis.
The SI Unit is newton meter (Nm)
The CGS Unit is dyne-cm
1𝑁𝑚 = 107
𝑑𝑦𝑛𝑒 − 𝑐𝑚
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7. Where F is the force applied and
d is the perpendicular distance
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𝑀𝑜𝑚𝑒𝑛𝑡 𝑜𝑓 𝐹𝑜𝑟𝑐𝑒 = 𝐹 × 𝑑
8. An object is said to be in equilibrium when
the forces acting on it produces no changes
in the state of rest or state of motion of the
object.
The two conditions for it would be:
◦ The resultant force on the object should be equal to
zero.
◦ The moment of force acting on the body at a point
should be zero.
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9. The principle of moments is the sum of anti-
clockwise moments about any point = sum of
the clockwise about the same point.
Two equal and opposite, parallel forces not
acting on the same line, are called a couple.
Moment of couple = force x perpendicular
distance (between the line of action of both
the forces)
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