Problem 2-98 - Linear Kinematics - Part 4

 A helicopter is traveling horizontally, straight toward a cliff. When $700 \;m$ from the cliff, it sends a sonar signal and $3.4 \;s$ later receives the reflected signal. Assuming the signal travels at $350 \;m/s$, determine the speed of the helicopter.

Accumulated Solution

$d = vt \\ d = (350 \;m/s)(3.4 \;s) = 1190\; m$

You should have:

$d = (350 \;m/s)(3.4 \;s) = 1190\; m$

How far is the signal echo from the cliff when it meets the helicopter?

(A)   $1190 - 700 = 490\; m$

(B)   $1190 + 700 = 1890\; m$

(C)   $(1/2)(1190 + 700) = 945 \;m$