A thread is wound 200 times round a reel of diameter 5 cm. Use the value 3 for it to find the approximate length of the thread i

Question

1 year ago

9

n metres.

1 answer:

Radda [10] · Answer 1 · 2021-01-11T05:40:41+03:00

Answer:

Length of the thread = 30 metres

Step-by-step explanation:

Length of the thread in one round of a reel = Circumference of the reel

C = $2\pi r$

Since radius of the reel = $\frac{\text{Diameter}}{2}$

= $\frac{5}{2}$

= 2.5 cm

Circumference of the reel = 2(π)(2.5)

= 5π

= 5×3

= 15 cm

Length of the thread wound in one round around the reel = 15 cm

Since, thread is wound 200 times round a reel, length of the thread

= 200 × 15

= 3000 cm

≈ 30 metres

Therefore, Option (B) will be the answer.