Question

Also number 19 please! 18 is 7.143

Answer 1

i am extremely stuck on this one

Answer 2

maximum height = 90

and maximum range = double of half range = 12


90 =u^2sinthita^2/2g

12 =u^2sin2thita/g

divide the 2 to get

90/12 = tanthita/4

tan thita = 30


since tan thita = 30 sin thita = 30/rooot(901)

put this in

12 =u^2sin2thita/g

and get the value of g

Answer 3

wait what is u^2??