Sam
Last Activity: 7 Years ago
in y axis displacement is -10m (taking -y axis as negative)
then s = ut + at2/2
-10 = (10sin30)t - 10t2/2 as velocity in yaxis is 10sin30=5 and a = -g as gravity is acting downward
-10 = 5t – 5t2
5t2 – 5t – 10 = 0
t2 – t – 2 = 0
(t – 2)(t + 1) = 0
so possible value of t will be 2 and -1 sec , as time cannot be negative so t=2sec
so velocity in y axis Vy = Uy – gt = 10sin30 – 10(2) = 5 – 20 = -15m/s
and velocity in x axis V
x = U
X = ucos30 = 10 (
)/2 = 5(
) m/s
velocity when strike V = 5
i – 5 j
let x be the angle made by velocity with ground
then tan x = 5 / 5
= 1/
=> x = 30 degree
