Question

A boat moves with a velocity of 4 m/s with respect to river to reach the exactly opposite end of the bank. If the speed of river is 3 m/s downstream. At what angle must the boat move with respect to ground move in order to reach the exactly opposite end of the bank ?

Answer 1

• .  TRICK NO.1: If the speed of a boat in calm water is x km / hour and the speed of the stream is y km / hour, then: (i). Speed of the boat in the direction of the stream = (x + y) km / hour (ii). Boat move in opposite direction of the stream = (x - y) km / hour Example: The speed of a boat in quiet water is 10 km / hour and the velocity of the current is 3 km / hour direction of the current (or stream) Downstream) and the speed of the boat in the opposite direction of the stream (or upward flow of the stream)? Solution: (i). Speed of the boat in the direction of the current = 10 + 3 = 13 km / h (ii). Speed of boat in opposite direction of stream = 10 - 3 = 7 km / h The movement in the direction of a swimmer's stream and opposite direction of the stream is 18 km / hour and 6 km / hour respectively. Find the speed and speed of the swimmer in the calm waters? Solution: TRICK NO.3: A sailor travels a certain distance in the direction of the stream and returns to the previous position. If the total time taken to go and arrive is T and the speed of boat and stream is x and y km / hour respectively.