A balloon leaves from a point P rises at a uniform speed. After 6 minutes, an observer situated at a distance of 450√3 meter from point P observes that angle of elevation of the balloon is 60°. Assume that point of observation and point P are on the same level. What is the speed (in m/s) of the balloon?

Answer: Option B

Solution

Answer: Option B

Solution:

$$\begin{array}{rl}& \tan 60^{\circ }=\frac{AP}{PO}\\ & \sqrt{3}=\frac{AP}{450\sqrt{3}}\\ & AP=450\sqrt{3}\times \sqrt{3}\\ & AP=1350\text{ m}\\ & \text{Speed}=\frac{\text{Distance}}{\text{Time}}\\ & =\frac{1350\text{ m}}{6\times 60\sec }\\ & =\frac{15}{4}\\ & =3.75\text{ m/s}\end{array}$$