The answer is C Hydroelectric
Answer:
The height of the bridge is 78.4 m.
Explanation:
Given;
time of the stone motion off the bridge, t = 4.0 s
acceleration due to gravity, g = 9.8 m/s²
The height of the bridge is given by;
h = ut + ¹/₂gt²
where;
u is the initial velocity of the stone, u = 0
h = ¹/₂gt²
h = ¹/₂(9.8)(4)²
h = 78.4 m
Therefore, the height of the bridge is 78.4 m.
Answer:
it's C and D... do you understand?
Answer:
avriage force F = 2722.5 N
Explanation:
For this problem we can use Newton's second law, to calculate the average force and acceleration we can find it by kinematics.
vf² = v₀² - 2 ax
The final carriage speed is zero (vf = 0)
0 = v₀² - 2ax
a = v₀² / 2x
a = 1.1²/(2 0.200)
a = 3.025 m / s²
a = 3.0 m/s²
We calculate the average force
F = ma
F = 900 3,025
F = 2722.5 N
