Here are the answers:
i) The simple machines discussed are lever, wedge, inclined plane, screw, wheel and axle, and pulley.
ii) Two examples of a lever are a see-saw and scissors.
iii) Some machines used at home include a sewing machine, washing machine, clock, scissors, spoon, and knife.
iv) A pulley is used for lifting heavy loads.
v) A knife and scissors are examples of machines used for cutting.
3. • We use machines all the time
• They are every where – at home, at
work, on the roads, in the sea and air.
• For example ; a cycle, a car and an
aeroplane are all machines.
cycle aeroplane car
4. • We use many machines at home e.g.
a sewing machine, a washing machine
and a clock.
• All Machines need energy to work.
• Machines make our work easier.
sewing machine
Washing machine
5. • We all use simple machines at
home.
• We use scissors for cutting the
paper.
• We use a spoon to lift the lid of a
can.
6. • We use a knife to cut fruits.
• Scissors, spoon and knife are all
machines.
Scissors
Spoon acting as lever
Knife
7. • A spoon is a kind of simple
machine called lever.
• A lever has an arm that can move
about on a point called fulcrum.
8. •A see-saw, a wheel barrow and a
pair of scissors are all levers.
See-saw
Wheel barrow
scissors
9. • A wedge is made by putting two
inclined planes together.
• It increases the force that we apply
and also changes the direction of
force.
• An axe and a knife are the example
of wedges.
KNIFE AXE
10. • The slope of the plank is a kind of
simple machine called the Inclined
plane.
• It helps in lifting heavy loads by
applying less force.
SLOPE OF PLANK LADDER
11. • A screw is a simple machine that is
used to hold two things together.
• It has a ridge called a thread which
is cut around like a spiral.
SCREW
12. • Most machines are made of wheels.
• A wheel turns on a rod called an axle.
• A car and train move on wheels, a
sewing machine has wheels and a
clock has different sizes of wheels.
Wheel and axle clock
13. • A pulley is a simple machine made up
of wheels.
• The wheel of a pulley turns on an axle.
• The pulley is used for lifting heavy loads.
14. i) Can you tell the name of all the
simple machines discussed in the
unit?
ii) Give any two examples of Lever?
iii) Name some machines used at
home?
iv) A pulley is used for lifting
___________.
v) Name the machine used for cutting?