Answer:
Vf = 11.04 m/s
Explanation:
First, we consider free fall motion with zero initial velocity. Using 2nd equation of motion:
h = Vi t + (1/2)gt²
where,
h = height of bridge = ?
Vi = Initial Speed = 0 m/s
t = time taken = 4.5 s
g = 9.8 m/s²
Therefore,
h = (0 m/s)(4.5 s) + (1/2)(9.8 m/s²)(4.5 s)²
Therefore,
h = 99.225 m
Now, we consider the forced motion when the youth throws the ball with some negative initial energy:
Vi = - Vi
t = 3 s
h = 99.225 m
Therefore,
99.225 m = - Vi(3 s) + (1/2)(9.8 m/s²)(3 s)²
Vi = (- 99.225 m + 44.145 m)/3 s
Vi = - 18.36 m/s
Now, we use this in 1st equation of motion for final velocity:
Vf = Vi + gt
Vf = -18.36 m/s + (9.8 m/s²)(3 s)
Therefore,
<u>Vf = 11.04 m/s</u>
Answer:
satisfaction, enjoyment and fair play
Aslaam 3lekm m3akm yaseen my 8nat alninkm
It is the the ecrins of light
Time = distance/time
time(hours)= 10/40
time(hours)=0.25
=15 minutes
