Explain how lubricating the wheels of the skateboard can increase the speed of the girl

When oil, grease or graphite is applied

between the moving part of a machine,

a thin layer is formed there and moving

surfaces do not directly rub against each

other (Fig. 12.13). Interlocking of

irregularities is avoided to a great extent.

Movement becomes smooth. The

substances which reduce friction are

called lubricants.

Less friction to stop the wheel from turning