AP Physics C: Mechanics : Energy
Study concepts, example questions & explanations for AP Physics C: Mechanics
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Example Questions
Example Question #11 : Energy
A man throws a 5kg ball straight up. At the top of its trajectory, the ball has a potential energy of 160 Joules. What is the highest point the ball reaches if it is thrown from the level of the ground?
The equation for potential energy is:
We can rearrange to solve for the height:
Plug in our given values to solve:
Example Question #21 : Work, Energy, And Power
A man throws a 5kg ball straight up. At the top of its trajectory, the ball has a potential energy of 160 Joules. At what velocity does the man initially throw the ball?
We can use conservation of energy to find the velocity required to launch the ball.
Example Question #21 : Work, Energy, And Power
A man launches a 5kg ball straight up from sea level. Disregarding drag, if the man would like to launch the ball into an escape trajectory from earth's gravity, approximately how fast must he launch the ball (in meters per second)?
In order to launch the ball at a velocity that escapes Earth's gravity, the kinetic energy must overcome the gravitational pull of the Earth. We can use conservation of energy to make the kinetic energy and gravitational potential energies equivalent.
Rearrange to solve for the escape velocity:
Finally, plug in our values and solve.
All AP Physics C: Mechanics Resources
