Question

If s varies jointly with t and the cube of r. How with s be affected if t is halved r is doubled

Answer 1

Given that s varies jointly with t and the cube of r.

We have to tell that if t is halved and r is doubled, what happens to s.

From the question, we can say that,.

$s\propto t\times(r)^3\Rightarrow s=ktr^3$

Given that t is halved and r is doubled. Then,

$\begin{gathered} s=k(\frac{t}{2})(2r)^3 \\ s=k(\frac{t}{2})(8r^3) \\ s=4\text{ktr}^3 \end{gathered}$

Thus, s becomes 4 times.