Page 148 - Active Science 5 Ebook and Activity

Door knob and bicycle pedal wheel are some more examples of wheel and axle.

Wheels on a wagon only touch the ground at one spot at a time, keeping the rest of the

wagon off the ground. This makes less friction, so that the wagon is easier to move.

Activity 13.2

Aim : To study the wheel and axle combination.

Material Required : Four bottle caps, two straws, two hard pieces of a broomstick,
matchstick holder and glue

Procedure : • Take the straws and broomsticks.

• Insert the broomsticks into the two straws.

• Fix the bottle caps on each end of each broomstick which would look
like a wheel and axle.

• Take glue and stick the bottle cap, straw and broomstick set up on a
matchstick holder. Be careful while adjusting the distance between
the caps and broomsticks.

• Put weights on top of the matchstick holder and push the set up.

Observation : The set up will move forward due to the wheel and axle.

Screw
A screw is a modified form of an inclined plane.

It is a simple machine that resembles a nail with
grooves in it. It is a hard metal (iron or steel) rod
with well-cut spiral threads on its surface. It is used
to hold things together effectively. A screw is preferred

over a nail because it holds things together over a longer Screw, Nut and Bolt
period of time and it does not come out easily.

A jack is a machine having a screw. It is used to lift heavy objects such as cars or trucks.

Wedge
Two inclined planes joined back to back make a wedge. The

two inclined planes are joined with a sharp edge in shape of a V.
Knife
Cut a piece of paper with the help of a knife from both the
edges (sharp and blunt edge). Note the difference— you will

Spade find that it is easier to cut the paper with the sharp edge as
compared to the blunt edge.

148 Active Science-5