Question

arc PP = As = v At. The tangent PQ at P to the trajectory gives the direction of the velocity at P. The
along OP, O is the centre of the force taken as the origin. In time At, the particle moves from P to P
area swept in At is the area of sector POP = ir sin a) PP/2 = (rv sin a) At/2.)
р
As
F
Р P.
020
M M
r sin a
Tr
nois the trejectory of the particle under the central force. At a position P, the force is directed​

Answer 1

Direction of velocity is always tangent to the path, so at the top of trajectory it is horizontal direction and acceleration due to gravity is always in vertically downward direction.

Hence, v and g are perpendicular to each other.