An object is projected for the hieght of 80 m above the ground with a velocity of 40ms-1 at the angle of 30° to the horizontal. The time of flight
-
A.
8 s -
B.
4 s -
C.
16 s -
D.
10 s
Correct Answer: Option B
Explanation
for a body projected at an angle θ to the horizontal, the time of the flight is given by T = (2u sin θ)/g =(2x 40)x sin (30)/10 =(2 x 40) x (0.5)/10 = 4.0secs.