Suppose you first walk 12.0 m in a direction 20 owest of north and then 20.0 m in a direction 40.0osouth of west. how far are you from your starting point, and what is the compass direction of a line connecting your starting point to your final position? (if you represent the two legs of the walk as vector displacements a and b , then this problem asks you to find their sum r = a + b . the two displacements a and b add to give a total displacement r having magnitude r and direction in degrees.

R=19.5m

= 4.65° S of W

Explanation:

Refer the attached fig.

displacement  of the x and y components

x-component displacement is () =

= A (20°) + B (40°)

= -12.0(20°) + 20.0(40°)

= -19.425m

x-component displacement is () =

=  A (20°) - B (40°)

= 12.0(20°) - 20.0(40°)

= -1.579

resultant displacement

∴

R =

=

=19.5m

=

=

= 4.65° S of W

sonar - device which is used to find the submit submarines, sankalp ship. sonar waves consists of a transmitter and detector which are installed in the observation centre on board of a ship. the ultrasonic waves are sent into the sea at high frequency about 1000 khz in all direction.