2. 𝕎ℍ𝔸𝕋 𝕀𝕊 𝕋ℍ𝔼 𝕋𝕌ℝℕ𝕀ℕ𝔾 𝔼𝔽𝔽𝔼ℂ𝕋 𝕆𝔽 𝔽𝕆ℝℂ𝔼
?
Forces can make objects turn if there is a hinge. A door opens and closes this way only. The
hinge is considered as the fulcrum or the pivot. The turning Effect of Force is called as the
Moment of Force. The moment of force is also called Torque or simply Moment.
The moment of force is the product of the force and the shortest distance from the pivot to
the point of application of the force.
M = F × d
The unit of the moment of force is Nm (Newton metre)
The moment of force through this equation explains why less force is required to open a door
by pushing at a place away from the hinge than at the place close to the hinge.
3. 𝕎𝕆ℝ𝕂𝕀ℕ𝔾 𝕆𝔽 𝔸 𝔹𝕆𝕋𝕋𝕃𝔼 𝕆ℙ𝔼ℕ𝔼ℝ
A bottle opener is a second class lever. In a second class lever, the load is in
between the fulcrum and the effort. The three forces at work on the
lever are:
1. The force of your hand as it pulls up on the handle of the lever:
Sometimes called the effort applied to the lever.
2.The force of the cap as it pulls down on the lip of the lever (this is
the paired force of the lever pulling up on the cap): Sometimes called
the load on the lever.
3.The force of the corner of the lid as it acts downwards on the lever
at the pivot.
With these three forces balanced, the lever stays still; it does not
accelerate off, either upwards or downwards.
All three forces are linked and so to lift off a particularly well fastened
cap, you need to pull up harder on the end of the opener (a bigger
effort). As a result the lip of the opener will push up more on the lid,
opening the bottle and the corner of the lid pulls down more (at the
pivot).
The whole point of the bottle opener is to produce a big force from
a small force, but the drawback is that you must push through a big
distance. Devices such as this are sometimes called force multipliers.
