Question

3 The radius of a circle is increasing at the rate of 0.7 cm/sec. What is the rate of increa
circumference?​

Answer 1

Answer:

Radius is increasing with the rate of 0.7 cm/sec

$rate \: with \: the \: circmference \: increase = 2\pi \times rate \: with \: radius \: is \: increasing \\ = 2 \times \frac{22}{7} \times 0.7 \\ = 2 \times \frac{22}{7} \times \frac{7}{10} \\ = \frac{2 \times 22}{10} \\ = \frac{44}{10} \\ = 4.4cm \: s {}^{ - 1}$

Rate of increasing circumference is

4.4 cm/sec or 0.044 m/sec