A rock weighing 98 newtons is pushed off the edge of a bridge 50 meters above the ground. What was the potential energy of the r
2 answers:
<u>Answer:</u> The potential energy of the rock before it began to fall is 4900 J
<u>Explanation:</u>
Force is defined as the mass multiplied by the acceleration of the object.
where,
F = force exerted on the object
m = mass of the object
g = acceleration due to gravity
Potential energy is defined as the energy possessed due to the height of the object.
Mathematically,
Or,
where,
= potential energy of the rock = ?
F = force applied on the rock = 98 N
h = height of the bridge from where the rock is thrown = 50 m
Putting values in above equation, we get:
Hence, the potential energy of the rock before it began to fall is 4900 J
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Answer:
0.833 N
Explanation:
Formula for Kinetic Energy
Formula for Potential Energy
First we need to find the vertical distance between the maximum-angle position and the pendulum lowest point:
Using the swinging point as the reference, the vertical distance from the maximum-angle (34 degree) position to the swinging point is:
At the lowest position, pendulum is at string length to the swinging point, which is 1.2 m. Therefore, the vertical distance between the maximum-angle position and the pendulum lowest point would be
y = 1.2 - 1 = 0.2 m.
As the pendulum is traveling from the maximum-angle position to the lowest point position, its potential energy would be converted to the kinetic energy.
By law of energy conservation:
Substitute and y = 0.2 m:
At lowest point, pendulum would generate centripetal tension force on the string:
We can substitute mass m = 0.25, rotation radius L = 1.2 m and v = 2 m/s: