Question

Two insects Chinki and Minki start to move in from point $A$ in straight line paths in a circle as shown. Chinki travels along $AP$ and Minki along $AM$, on reaching point $M$, Minki insect changes its direction and moves parallel to the line $AP$ and reaches the diametric opposite point $B$. The radius of circle is $5\text{m}$ and line $AP$ makes an angle of ${37}^{\circ }$ with the diameter $AB$. If the speed of Minki insect along $AMB$ is $2\text{m/s}$ constant then how much time (in $\text{sec}$) will Minki take to reach $B$ from $A$.

Answer 1

Angle in a semicircle is a right angle.
So, $\angle AMB={90}^{\circ }$
Hence, side $AM=6\text{m}$ and $MB=8\text{m}$
Therefore,
Total distance travelled $=AM+MB=14\text{m}$
Since speed was constant at $2\text{m/s}$ throughout.
So, time taken $=\frac{14}{2}=7\text{s}$