91Ó°ÊÓ

• A human wave travels a distance in terms of seats, d =853
• The time to travel 853 seats, t =39 s.
• The time required for spectators to respond, t =1.8 s

The speed is equal to the distance traveled by a wave in a given time.

In the given problem, the distance is measured in terms of the number of seats. Therefore, the speed of the wave can be calculated knowing the number of seats the wave has traveled in the given time.

Formula:

Speed of a body in motion, $v=\frac{d}{t}$ (i)

The equation for velocity using equation (i)and the given values is given by:

$$\begin{gathered} v=\frac{853\mathrm{seats}}{39\mathrm{s}} \\ =21.87\mathrm{seats}/\mathrm{s} \\ â‰\dots 22\mathrm{seats}/\mathrm{s} \end{gathered}$$

Hence, the value of wave speed is 22 seats/s

The width can be calculated using the same equation considering the distance as width using equation (i) can be given as:

$$\begin{gathered} w=v×t \\ =21.87×1.8 \\ =39\mathrm{seats} \end{gathered}$$

Hence, the width in terms of seats is 39 seats .