Question

Hair grows at an average rate of 3 x 10.9 m/s. How long will it take to grow a 10 cm strand?

Answer 1

It will take 33,3333,333.33secondsto grow a 10cm (0.1m) strand.

Why?

It's a conversion problem, so, to solve it, we need to make the units consistent.

Let's convert from cm to meters, since the rate of grow is in m/s.

$1m=100cm\\\\10cm*\frac{1m}{100cm}=0.1m$

Now, calculating we have:

$Grow=rate*time\\\\0.1m=3x10^{-9}\frac{m}{s}*time\\\\time=\frac{0.1m}{3x10^{-9}\frac{m}{s}}=33,3333,333.33seconds$

Hence, It will take 33,3333,333.33seconds to grow a 10cm (0.1m) strand.

Have a nice day!