Kinetic energy is energy of motion. Pick choice-A, at the top of the swing, where she stops moving & then goes the other way.
Answer:
a) 19.4 m/s
b) 19 m/s
Explanation:
a) In the given question,
the potential energy at the initial point = Ui = 0
the potential energy at the final point = Uf = mgh
the kinetic energy at the initial point = Ki = 1/2 mv₀².
the kinetic energy at the final point = Kf = 0
work done by air= Ea= fh = 0.262 N
Now, using the law of conservation of energy
initial energy= final energy
Ki +Ui = Kf + Uf +Ea
1/2 mv₀² + 0 = 0 + mgh + fh
1/2 mv₀² = mgh + fh
h = v₀²/ 2g (1 +f/w)
calculate m
m= w/g = 5.29 /9.8
= 0.54 kg
h = 20 ²/ (2 x9.80) x (1 0.265/5.29)
h = 19.4 m.
b) 1/2 mv² + 2fh = 1/2 mv₀²
Vg = 19 m/s
The pressure exerted by the concrete cylinder is 2.60 pound/in².
We need to know about the pressure to solve this problem. Pressure is a unit that describes how much force is applied to a surface area. It can be determined as
P = F / A
where P is pressure, F is force and A is area.
From the question above, we know that
F = 375 pound
A = 144 in²
By substituting the given parameters, we can calculate the pressure
P = F / A
P = 375 / 144
P = 2.60 pound/in²
Thus, the pressure should be 2.60 pound/in².
Find more on pressure at: brainly.com/question/25965960
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The Answer is C. the distance light travels in a year
