A force of 5 units acts on a particle in the direction to the east and another force of 4 units acts on the particle in the direction northeast. The resultants of the two forces is

A.
(sqrt{3}) units 
B.
3 units 
C.
(sqrt{41 + 20 sqrt{2}}) units 
D.
(sqrt{41 – 20 sqrt{2}}) units
Correct Answer: Option C
Explanation
Force to the east = 5 units
force to the North – east = 4 units.
Resultant of the two forces is the square root
52 + 42 = 41 and plus the sum of its resistance
5 x 4(sqrt{2}) = 20(sqrt{2})
= (sqrt{41 + 20 sqrt{2}}) units