Answer:
20.05 seconds
Explanation:
Given that:
v² = u² + 2as
v = final velocity
u = initial velocity
a = acceleration
s = distance
a = negative acceleration = - 0.43
s = distance = 86.5
v = 0
0 - 2(0.43)(86.5) = u²
74.39 = v²
U = sqrt(74.39)
U = 8.6249
From ;
t = Time in seconds
t = (v - u) / a
t = (0 - 8.6249) / - 0.43
t = 20.057
The formula for speed is distance traveled divided by time
Your answer would be B, Reflected light! hope this helps
Answer:
A. 2.41 s.
B. 24.3 m/s.
Explanation:
vf = vi + 2a*t
where, vf = final velocity
= 0 m/s
vi = final velocity
= 1.5 m/s
a = 9.8 m/s^2
A.
ti = 1.5/(9.8 * 2)
= 0.08 s
Vf^2 = Vi^2 + 2a*s
1.5^2 = 2 * 9.8 * s
S = 0.115 m
Time taken to drop into the water,
30.115 = 1.5*to + 4.9*to^2
to = 2.33 s
Total time taken = ti + to
= 2.33 + 0.08
= 2.41 s.
B.
Vo = 0 m/s
S = 30.115 m
Vf = ?
Using,
Vf^2 = Vo^2 + 2*a*s
= sqrt (2*9.8*30.115)
= 24.3 m/s.