(A) Since, change in momentum =∫Fdt
therefore, since only force acting is F=mg
which is depends on mass of the object therefore, change in momentum is independent of projected velocity.
(B)At highest point object travels parallel to horizontal surface therefore angle at highest point is zero.
(C)At highest point velocity is minimum therefore, at highest point KE is minimum.
(D)Since there is no horizontal force therefore, no change in horizontal component of velocity.
A-2,
B-3
C-4
D-1