c. Just before the ball hits the ground, how are its speed and kinetic energy related? (1 point)
• Both speed and kinetic energy are at their lowest values.
Both speed and kinetic energy are at their greatest values.
• Speed is at its highest value, while kinetic energy is at its lowest value.
• Speed is at its lowest value, which kinetic energy is at its highest value.
c. Speed is at its highest value, while kinetic energy is at its lowest value.
• Speed is at its highest value, while kinetic energy is at its lowest value.
To determine the relationship between the speed and kinetic energy of a ball just before it hits the ground, we need to understand the concept of kinetic energy.
Kinetic energy is the energy possessed by an object due to its motion, and it is directly related to the object's speed. The formula for kinetic energy is given by:
Kinetic energy = 1/2 * mass * velocity^2
Now, considering the scenario where the ball is just about to hit the ground, we can analyze the options given:
• Both speed and kinetic energy are at their lowest values - This option is incorrect because just before the ball hits the ground, it is moving at a certain speed, indicating that the speed and kinetic energy are not at their lowest values.
• Both speed and kinetic energy are at their greatest values - This option is also incorrect because as the ball is about to hit the ground, it is losing speed due to the opposing force of gravity. Therefore, the speed and kinetic energy are not at their greatest values.
• Speed is at its highest value, while kinetic energy is at its lowest value - This option is also incorrect. As mentioned earlier, the ball is losing speed as it approaches the ground, so the speed cannot be at its highest value just before hitting the ground.
• Speed is at its lowest value, while kinetic energy is at its highest value - This option is correct. Just before the ball hits the ground, its speed is decreasing to zero. However, since the ball still possesses some mass, the kinetic energy is not zero. Therefore, the speed is at its lowest value, while the kinetic energy is at its highest value.
In summary, the correct answer is: Speed is at its lowest value, while kinetic energy is at its highest value.