A police car is rapidly approaching you at a stop light. Explain what happens to the frequency of the sound as the police car dr
1 answer:
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Answer:
Explanation:
Given:
length of ladder
weight of ladder
position of firefighter
weight of firefighter
angle of ladder
Unknown:
force of the wall on the ladder
force of friction on base of ladder
normal force on base of ladder
From the free body diagram of the sketch you get 3 equations:
Solving the equations gives:
a)
b)
c) Using the result from b and solving for
Answer:
B) t = 1.83 [s]
A) y = 16.51 [m]
Explanation:
To solve this problem we must use the following equation of kinematics.
where:
Vf = final velocity = 0
Vo = initial velocity = 18 [m/s]
g = gravity acceleration = 9.81 [m/s²]
t = time [s]
Note: the negative sign in the above equation means that the acceleration of gravity is acting in the opposite direction to the motion.
A) The maximum height is reached when the final velocity of the ball is zero.
0 = 18 - (9.81*t)
9.81*t = 18
t = 18/9.81
t = 1.83 [s], we found the answer for B.
Now using the following equation.
where:
y = elevation [m]
Yo = initial elevation = 0
y = 18*(1.83) - 0.5*9.81*(1.83)²
y = 16.51 [m]