A projectile is fired with an initial speed of 11.3 m/s at an angle of 60° above
ID: 1963236 • Letter: A
Question
A projectile is fired with an initial speed of 11.3 m/s at an angle of 60° above the horizontal from on top of a 49 m high cliff. Determine thea) Time to reach maximum height
b) Maximum height above the base of the cliff reached by the projectile (from ground level)
c) Total time in the air
d) Horizontal range of the projectile
Explanation / Answer
V = 11.3m.sec angle a = 60 V_verticel = V_v = 11.3 sin60 = 9.79 V_Horizontal = 11.3cos60 = 5.65 a) At max height v = 0 v = u +at 9.79/9.8 = t => t = 1sec b) max height be H H = ut + .5at^2 => H = 9.79*1 + .5*9.8 = 19.59m c) Total time n the air be T T = 1 + time to fall (19.59+49)m h = 68.59 h = ut+ .5at^2 => t = square root(68.59*2/9.8) 3.74 sec T =1+ 3.74 = 4.74 sec d) range = t*V_h = 4.74*5.65 = 26.78m