Answer:
29.448 [tex]ms^{-1}[/tex]
Explanation:
first determine the distance from the top of the roof to the friends head.
Since he is 1.80 min height ,
distance = 46.0-1.80
= 44.2 m
egg is dropped from rest means that its starting velocity is zero. It has to travel 44.2 m subjected to the gravitational acceleration
Applying Motion equation
[tex]v^{2}=u^{2}+2as[/tex]
where v= end velocity (speed)
u=Starting velocity
a= acceleration
s= Distance
(Let gravitational acceleration assumed as [tex]9.81 ms^{-2}[/tex]
[tex]v^{2} =0^{2} +2*9.81*44.2\\v^{2} =867.204\\v=\sqrt{867.204} \\v=29.448 ms^{-1}[/tex]
Answer:
The speed of egg is 14.73 m/s
Explanation:
Given the height of building (H) = 46 m
The height of friend (h) = 1.8 m
Distance for the egg to travel (s) = H – h = 46 – 1.8 = 44.2 m
Applying second equation of motion,
[tex]s=u t+\frac{1}{2} g t^{2}[/tex]
u = 0 (as the egg is starting from the rest)
g = 9.81 [tex]m/s^2[/tex](as the object is falling)
Substituting the values,
44.2=0+[tex]\frac{1}{2} \times9.81 \times t^{2}[/tex]
[tex]t^{2}=\frac{44.2 * 2}{9.81}[/tex]
[tex]t^2[/tex] = 9
t = 3 sec
Calculating speed,
Speed = [tex]\frac{\text { Distance }}{\text { time }}[/tex]
Speed = [tex]\frac{44.2}{3}=14.73 \mathrm{m} / \mathrm{s}[/tex]
Therefore, the speed of egg is 14.73 m/s
