A person throws a ball up into the air, and the ball falls back toward Earth. At which point would the kinetic energy be the lowest?(1 point)
Responses
when the ball leaves the person’s hand
when the ball leaves the person’s hand
at a point before the ball hits the ground
at a point before the ball hits the ground
at a point when the ball is still rising
at a point when the ball is still rising
when the ball is at its highest point
at a point when the ball is still rising
A book is at rest on a flat table. A person gives the book a shove and it slides across the table. The book eventually comes to rest again near the edge of the table. How does the potential and kinetic energy change during this process?(1 point)
Responses
The potential and kinetic energy are the same while the book is sitting on the table. They both increase when the book is shoved and then decrease as the book comes to rest again.
The potential and kinetic energy are the same while the book is sitting on the table. They both increase when the book is shoved and then decrease as the book comes to rest again.
The potential stays the same since the book is on the table. The kinetic energy stays the same since the book was only shoved.
The potential stays the same since the book is on the table. The kinetic energy stays the same since the book was only shoved.
The potential energy will stay the same as long as the book stays on the table. The kinetic energy increases when the book is shoved and then gradually decreases as it slides across the table and then comes to rest on the edge.
The potential energy will stay the same as long as the book stays on the table. The kinetic energy increases when the book is shoved and then gradually decreases as it slides across the table and then comes to rest on the edge.
The potential energy increases as the book is pushed across the table. The kinetic energy stays the same since the book was shoved.
The potential energy will stay the same as long as the book stays on the table. The kinetic energy increases when the book is shoved and then gradually decreases as it slides across the table and then comes to rest on the edge.
Which is a good description of potential energy?(1 point)
Responses
energy of reaction
energy of reaction
stored energy
stored energy
conserved energy
conserved energy
energy of motion
stored energy
The kinetic energy of the ball would be the lowest at the highest point of the ball's trajectory.
To determine when the kinetic energy of the ball is the lowest, we need to understand what kinetic energy is and how it changes during the ball's motion.
Kinetic energy is the energy an object possesses due to its motion. It depends on both the mass of the object and its velocity. The formula for kinetic energy is KE = 0.5 * mass * velocity^2.
At the point where the ball leaves the person's hand, it has an initial velocity upward, imparted by the person's throw. As it rises, its velocity decreases due to the gravitational force acting against it. Thus, its kinetic energy decreases as it moves upward.
Similarly, as the ball reaches its highest point, its velocity becomes momentarily zero before reversing direction and falling back down towards the ground. At this point, the ball's kinetic energy is also at its lowest since the velocity is zero.
Therefore, the correct answer is "at a point when the ball is at its highest point" because at this point, the ball has no velocity and, consequently, the lowest kinetic energy.