A good description of kinetic energy is energy of motion.
Which is a good description of kinetic energy?(1 point) Responses conserved energy conserved energy stored energy stored energy energy of motion energy of motion energy from the sun
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A person throws a ball up into the air. At which point in its path will the ball have the greatest potential energy?(1 point) Responses when the ball reaches its highest point when the ball reaches its highest point when the ball leaves the person’s hand when the ball leaves the person’s hand when the ball is still rising when the ball is still rising when the ball hits the ground
The ball will have the greatest potential energy when the ball reaches its highest point.
Use the table of information from an investigation to answer the question. Student Depth of Object in Sand (cm) Maddie 1.8 Naveed 4.0 Two students drop an object into sand from a height of 1.5 meters. They record the depth of the hole made in the sand by each student’s object. What is the most likely explanation for the results? (1 point) Responses Naveed’s object had greater kinetic energy. Naveed’s object had greater kinetic energy. Maddie’s object had a faster drop speed. Maddie’s object had a faster drop speed. Maddie’s object has a smaller width. Maddie’s object has a smaller width. Naveed’s object has less mass.
The most likely explanation for the results is Naveed’s object had greater kinetic energy.
A student wants to determine the effect of mass on kinetic energy. She will drop two balls of the same size into a pool of water. Which investigation method should the student use?(1 point) Responses She should drop two balls of the same mass from different heights. She should drop two balls of the same mass from different heights. She should drop two balls with different masses from the same height. She should drop two balls with different masses from the same height. She should drop two balls with different masses from different heights. She should drop two balls with different masses from different heights. She should drop two balls of the same mass from the same height.
The student should use the method of dropping two balls with different masses from the same height. This will help her determine the effect of mass on kinetic energy while keeping other variables constant.
Which falling object will result in the least kinetic energy when it collides with the ground?(1 point) Responses 10 grams of dirt falling at 2 m/s 10 grams of dirt falling at 2 m/s 100 grams of dirt falling at 15 m/s 100 grams of dirt falling at 15 m/s 100 grams of water falling at 10 m/s 100 grams of water falling at 10 m/s 10 grams of water falling at 1 m/s 10 grams of water falling at 1 m/s
To calculate kinetic energy (KE), we use the formula:
\[ KE = \frac{1}{2} mv^2 \]
where \( m \) is the mass and \( v \) is the velocity.
Let's calculate the kinetic energy for each option:
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10 grams of dirt falling at 2 m/s: \[ KE = \frac{1}{2} (0.01 , \text{kg}) (2 , \text{m/s})^2 = 0.01 , \text{kg} \cdot 4 , \text{m}^2/\text{s}^2 = 0.02 , \text{J} \]
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100 grams of dirt falling at 15 m/s: \[ KE = \frac{1}{2} (0.1 , \text{kg}) (15 , \text{m/s})^2 = 0.05 , \text{kg} \cdot 225 , \text{m}^2/\text{s}^2 = 11.25 , \text{J} \]
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100 grams of water falling at 10 m/s: \[ KE = \frac{1}{2} (0.1 , \text{kg}) (10 , \text{m/s})^2 = 0.05 , \text{kg} \cdot 100 , \text{m}^2/\text{s}^2 = 5 , \text{J} \]
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10 grams of water falling at 1 m/s: \[ KE = \frac{1}{2} (0.01 , \text{kg}) (1 , \text{m/s})^2 = 0.005 , \text{kg} \cdot 1 , \text{m}^2/\text{s}^2 = 0.005 , \text{J} \]
Comparing the kinetic energies:
- 10 grams of dirt at 2 m/s: 0.02 J
- 100 grams of dirt at 15 m/s: 11.25 J
- 100 grams of water at 10 m/s: 5 J
- 10 grams of water at 1 m/s: 0.005 J
The falling object that will result in the least kinetic energy when it collides with the ground is 10 grams of water falling at 1 m/s.
Use the image to answer the question. This image of a roller coaster is designed to show important information about potential and kinetic energy. One of these labeled pieces of information is incorrect. Which information is wrong, and why? (1 point) Responses The roller coaster would only have potential energy at the point labeled “gravitational potential energy and kinetic energy.” The roller coaster would only have potential energy at the point labeled “gravitational potential energy and kinetic energy.” The spot with the “maximum kinetic energy” should be on the lowest point of the roller coaster, at the far left side on the bottom. The spot with the “maximum kinetic energy” should be on the lowest point of the roller coaster, at the far left side on the bottom. The spot marked “maximum gravitational potential energy” should be on the lowest point of the roller coaster, at the far left side on the bottom. The spot marked “maximum gravitational potential energy” should be on the lowest point of the roller coaster, at the far left side on the bottom. The roller coaster would only have kinetic energy at the point labeled “gravitational potential energy and kinetic energy.” The roller coaster would only have kinetic energy at the point labeled “gravitational potential energy and kinetic energy.” Skip to navigation
The information that is incorrect is: The roller coaster would only have potential energy at the point labeled “gravitational potential energy and kinetic energy.”
This statement is misleading because at that point, the roller coaster will have both potential energy (due to its height) and kinetic energy (due to its speed). Most roller coasters convert potential energy to kinetic energy and vice versa as they move along the track, so it is inaccurate to say that it would only have potential energy at that point.
In contrast, the maximum kinetic energy should indeed be at the lowest point of the roller coaster, and the maximum gravitational potential energy would be at the highest point of the track.
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