Question

A child flies a kite on a breezy day, suddenly a burst of wind causes the kite to fly in $0.8m$ radius circles every second. If the circular motion were converted to a straight down speed, how fast would the kite dive toward the ground?

• A. $3.14m/s$
• B. $5m/s$
• C. $6.28m/s$
• D. $9.8m/s$
• E. $15.7m/s$

Answer 1

Answer: (B)

$5m/s$

Angular velocity of kite $\omega =\theta /t=2\pi /1=2\pi$ rad/s because it completes one circle ($2\pi$ radian) in $1$ second ,

now given that $r=0.8m$

therefore linear velocity,with which kite comes straight down $v=r\omega =0.8\times 2\pi =5.0m/s$