20. A body of mass 20kg lies on a horizontal floor
and is acted on by constant forces of
magnitudes 100N and mN in the directions
180° and 060° respectively, where m is a
constant. The body begins to move in the
direction 090°. If there is also a resistance of
per kg to the motion of the body,
(a) calculate the value of m and the magnitude
of the resultant force acting on the body.
(b) Find the acceleration of the body.