Page 121 - Viva ICSE Science 5 : E-book

fulcrum
load
In class two levers, the load is in between eff ort load
the fulcrum and the eff ort. Bottle
openers, nut crackers and wheel barrows fulcrum
eff ort
are examples of class two levers.
C
Class two leverlass two lev
fulcrum

In class three levers, the eff ort is in
eff ort
between the fulcrum and the load.
eff ort Tongs and fi shing rods are examples

load load of class three levers.
fulcrum
Class three lever

TIME TO REVISE

Explain the following.
1. Machine 2. Class one levers 3. Class three levers

ACTIVITY TIME

Using a pair of scissors, a nut-cracker and a pair of tongs understand the working of class one,
class two and class three levers.

Inclined plane

An inclined plane is a sloping or a slanting
surface which connects a lower level to a

higher level. It helps to move heavier objects
to a height. It takes less eff ort to push a load
in a trolley up a slope than to lift the load

and climb up the stairs. Children’s slide in
a playground, ramps for wheelchairs and
sloping roads are some examples of inclined planes. Inclined plane

Pulley

A pulley is a simple machine made with a rope or chain wrapped around a wheel. It

changes the direction of force and thus makes it easier to lift things to some height.

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