-- The two negative charges both attract the positive charge at the origin.
-- The -4C charges are horizontally symmetrical, so there's no net horizontal force on the +3C at the origin.
-- However, the -4C both pull it down.
-- So the net force on the +3C at the origin is directed straight down.
The arrow labelled <em>' C '</em> represents the net force on it.
Answer:
C
Explanation:
When the can is floating below the surface of the lake the principle of buoyancy applies. The water will be exerting force in the upward direction equals to the weight if the can.
Answer:
the pilot should head the plane 
towarrds south- west
Solution:
The airspeed of the airplane, v = 280 km/h
The velocity of the wind, v' = 52 km/h South-west
Angle, 
Now, measured angle in the clockwise direction from North:
Now,
south- west
That's up to you because you have to go through the book to see their expressions
