Answer:
(a). The width of the river is 90.5 m.
The current speed of the river is 3.96 m.
(b). The shortest time is 15.0 sec and we would end 59.4 m east of our starting point.
Explanation:
Given that,
Constant speed = 6.00 m/s
Time = 20.1 sec
Speed = 9.00 m/s
Time = 11.2 sec
We need to write a equation for to travel due north across the river,
Using equation for north
Put the value in the equation
....(I)
We need to write a equation for to travel due south across the river,
Using equation for south
Put the value in the equation
....(II)
(a). We need to calculate the wide of the river
Using equation (I) and (II)
We need to calculate the current speed
Using equation (I)
(b). We need to calculate the shortest time
Using formula of time
We need to calculate the distance
Using formula of distance
Hence, (a). The width of the river is 90.5 m.
The current speed of the river is 3.96 m.
(b). The shortest time is 15.0 sec and we would end 59.4 m east of our starting point.