Question

A piece of wire is wound 50 times round a circular tin of radius 9.8 cm. What is the length of the piece

of wire used? Give your answer in metres . correct to 2 decimal places.(Use π: 3.14)

Answer 1

Answer: The length of the wire is the circumference of the circle formed by the tin multiplied by the number of times the wire is wound around it.

The circumference of a circle with radius r is 2πr. Therefore, the circumference of the tin is:

circumference = 2π(9.8 cm) = 61.56 cm

The wire is wound around the tin 50 times, so the total length of the wire is:

total length = 50 × circumference = 50 × 61.56 cm = 3078 cm

Converting to meters, we get:

total length = 3078 cm ÷ 100 cm/m = 30.78 m

Rounding to 2 decimal places, the length of the wire used is 30.78 meters.