At the low point in its swing, a pendulum bob with a mass of 0.9 kg has a velocity of 8 m/s.
The kinetic energy is of course 29 J.
But now.... (b) Ignoring air resistance, how high will the bob swing above the low point before reversing direction?
Please explain how to do this :/. Thanks!
The kinetic energy is of course 29 J.
But now.... (b) Ignoring air resistance, how high will the bob swing above the low point before reversing direction?
Please explain how to do this :/. Thanks!
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At the high point in its swing, all of its kinetic energy will have been converted to gravitational energy (do you see why?)
Thus, we can set the gravitational energy at the top of its swing equal to its kinetic energy at the bottom part of its swing (this is because of the law of conservation of energy).
Execution:
mgh = K.E. (kinetic energy)
(0.9 kg)(9.81 m/s²)(h) = 29 J
h = 3.2846 m ≈ 3.3 m
Thus, we can set the gravitational energy at the top of its swing equal to its kinetic energy at the bottom part of its swing (this is because of the law of conservation of energy).
Execution:
mgh = K.E. (kinetic energy)
(0.9 kg)(9.81 m/s²)(h) = 29 J
h = 3.2846 m ≈ 3.3 m