a) 15.8 ms-1
b)869 m
Step-by-step 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