Question

a boat operator in a boat can travel 15m/sec in still water he tries to cross a river which is flowing at 5 m/sec south. A) what is the resultant velocity of the boat? B) The takes exactly 55 seconds to cross the river in the resulting velocity, how many meters did the boat travel?

Answer 1

a) 15.8 ms-1

b)869 m

Explanation:

We have to obtain the resultant velocity by the Pythagorean theory;

R^2= V1^2 + V2^2

Where

R= resultant velocity of the boat

V1= velocity of the boat

V2= velocity of the flowing river

Thus;

R= √V1^2 + V2^2

R= √15^2 + 5^2

R= √225 + 25

R= √250

R= 15.8 ms-1

B) from

v= s/t

Where

v= velocity (resultant velocity in this case)

s= distance

t= time (55 secs)

s= vt

s= 15.8×55

s= 869 m