Question

Example 4.3 A motorboat is racing
towards north at 25 km/h and the water
current in that region is 10 km/h in the
direction of 60° east of south. Find the
resultant velocity of the boat.​

Answer 1

Answer:

the resultant velocity is

$25 - 10 \cos(60) \\ = 25 - 10 \times \frac{1}{2} \\ = 25 - 5 \\ = 20km.h {}^{ - 1}$

Answer 2

Answer

15√2

Explanation:

Speed of current due south is 10cos60 which is 10×1/2=5..

resultant speed of motorboat due north=25-5= 20..

now speed of current due east is 10cos30=5√2..

now 5√2 + 20 (vector sum)=√450=15√2