Answer:
Time = 1.61 seconds
Explanation:
Using the equation displacement of a trajectory motion in the y plane
Y = u t sin ů - ½gt²....equation 1 where
Y= vertical displacement =4.1
U = initial velocity = 15m/s
g = acc. Due to gravity = 10m/s
Ů = angle of trajectory = 45
t = time to reach fan on its way down
Sub into equ 1
4.1 = 15t sinů - ½ * 10t²
4.1 = 10.61t - 5t²
Solve using quadratic formula
t =[-B±( -B² -4AC)^½]/2A....equation 2
Where A = 5, B=10.61, C =4.1
Substitute A,B,C into equ2
t = (10.61±5.53)/10
t = 0.508seconds or 1.61seconds
Since it is on its way down t= 1.61 seconds
