Reducing friction

friction can be reduced by

• providing wheels

• lubricating

• polishing

• all of these

which would not be a way of reducing friction

• by polishing moving parts

• by lubricating moving parts

• by making surface rough

• by making surface smooth

identify the activity ,it will

• increase friction

• damage machine parts

• not affect friction

• decrease friction

Wheels on a skateboard most likely experiences-

• reduced friction

• increased friction

• no any change on friction

• can not say

by these processes, we can

• increase friction

• decrease friction

• there will be no any affect on friction

• can not say

An example of force can change the shape and size of an object is

• stretching a spring

• pushing a cart

• pulling a bag

• catching a ball

drawing a bucket of water from a well is

• push

• pull

• magnetic force

• gravitational force

it is an example of

• kinetic friction

• rolling friction

• static friction

• non of these

Fish and birds have naturally ........... bodies

the bodies of aeroplanes are also streamlined to minimize

• friction

• static friction

• drag

• rolling friction