Summary Biotechnology

BOATS & STREAMS

,EFFECTIVE SPEED
Effective speed is defined as the final speed
of a body influenced by an external force/speed.
Let's take the instance of riding a bi-cycle
against the wind. Though you pedal harder you
will not be able to travel at the speed of your
pedaling because of the resistance offered by the
wind. Here, the effective speed is the difference
between the speed of the bi-cycle and that of the
wind.

, However, when you ride in the direction of
the wind, you benefit from the speed of the
wind. Here, you travel at a speed more than the
speed of your pedaling. Thus the effective speed
becomes the sum of the speeds of the bi-cycle
and the wind.
The concept of effective speed is solely
applied in the topics Boats and Streams and
Escalators.

, BOATS AND STREAMS
These problems are governed by the following
results.
•Downstream (along the current) speed (D)
= boat speed (B) + current (stream) speed (C)
•Upstream (against the current) speed (U)
= boat speed – current (stream) speed
•Speed of the boat = average of downstream
and upstream speeds
•Speed of the current = half the difference of
downstream and upstream speeds