When the pendulum is held at the top of its swing, it has gravitational potential energy. This energy is due to its height relative to the lowest point of the swing. The higher the pendulum is lifted, the more gravitational potential energy it possesses. At this point, the kinetic energy is zero because the pendulum is momentarily at rest before being released.
A pendulum is held at the top of its swing. The person holding the pendulum lets go, and the pendulum is allowed to swing freely. Answer the following questions about the pendulum.
a. When the pendulum is held at the top of its swing, what type of energy does it have?
11 answers
As the pendulum swings freely, what is happening to its energy?(1 point)
As the pendulum swings freely, its gravitational potential energy is converted into kinetic energy. When the pendulum is released and moves downward, its height decreases, and thus its gravitational potential energy decreases while its speed increases, resulting in an increase in kinetic energy. At the lowest point of the swing, the pendulum has maximum kinetic energy and minimum potential energy. As the pendulum swings back upward, the kinetic energy decreases while potential energy increases again, and this transformation between potential and kinetic energy continues as the pendulum swings back and forth. This process demonstrates the principle of conservation of mechanical energy in a frictionless system.
As the pendulum swings freely, what is happening to its energy?(1 point)
KE converts to KE, and then total energy becomes zero
PE converts to KE, and then total energy becomes zero
KE converts to PE, and then total energy becomes zero
KE converts to PE, and then total energy becomes zero
KE converts to PE as it falls, and then PE converts to KE as it rises
KE converts to PE as it falls, and then PE converts to KE as it rises
PE converts to KE as it falls, and then KE converts to PE as it rises
KE converts to KE, and then total energy becomes zero
PE converts to KE, and then total energy becomes zero
KE converts to PE, and then total energy becomes zero
KE converts to PE, and then total energy becomes zero
KE converts to PE as it falls, and then PE converts to KE as it rises
KE converts to PE as it falls, and then PE converts to KE as it rises
PE converts to KE as it falls, and then KE converts to PE as it rises
The correct statement is:
PE converts to KE as it falls, and then KE converts to PE as it rises.
This accurately describes the transformation of energy in a pendulum as it swings. Gravitational potential energy (PE) converts to kinetic energy (KE) as the pendulum descends, and then kinetic energy converts back to potential energy as the pendulum ascends. Throughout this motion, the total mechanical energy remains constant, assuming there is no external friction or air resistance.
When are kinetic energy and potential energy equal in magnitude (equal in amount)?
They are equal at every position.
They are equal at every position.
They are equal at the bottom position.
They are equal at the bottom position.
They are equal half-way between the top position and the bottom position.
They are equal half-way between the top position and the bottom position.
They are equal at the top position.
They are equal at every position.
They are equal at every position.
They are equal at the bottom position.
They are equal at the bottom position.
They are equal half-way between the top position and the bottom position.
They are equal half-way between the top position and the bottom position.
They are equal at the top position.
They are equal half-way between the top position and the bottom position.
In a simple pendulum, kinetic energy (KE) and potential energy (PE) are equal in magnitude at the midpoint of the swing, which is halfway between the highest point (top position) and the lowest point (bottom position). At this point, the pendulum has equal amounts of kinetic and potential energy as it swings through.
The image shows an apple falling from a window ledge 6 meters off the ground. a. At which position is the potential energy the greatest?
____6
____4
____2
_____0
____6
____4
____2
_____0
The potential energy of the falling apple is greatest at the highest position. Since the apple is initially 6 meters off the ground when it is held at the window ledge, the position at which the potential energy is greatest is:
____6
At this height, the apple has maximum gravitational potential energy. As it falls and gets closer to the ground, its potential energy decreases while its kinetic energy increases.
b. At what position is the kinetic energy the greatest?
just below 6
just above 0
just above 0
0 CM
just below 6
just above 0
just above 0
0 CM
The kinetic energy of the falling apple is greatest just before it hits the ground (position 0 cm).
So the correct answer is:
just above 0
At this point, the apple has converted most of its gravitational potential energy into kinetic energy, resulting in the highest speed and therefore the maximum kinetic energy just before impact.
35 answers