Energy of Motion Unit Test
5 of 105 of 10 Items
Question
Which falling object will result in the least kinetic energy when it collides with the ground?(1 point)
Responses
100 grams of water falling at 10 m/s
100 grams of water falling at 10 m/s
10 grams of dirt falling at 2 m/s
10 grams of dirt falling at 2 m/s
10 grams of water falling at 1 m/s
10 grams of water falling at 1 m/s
100 grams of dirt falling at 15 m/s
10 grams of water falling at 1 m/s
To determine which falling object will result in the least kinetic energy when it collides with the ground, we need to consider the formula for kinetic energy:
Kinetic energy (KE) = 1/2 * mass * velocity^2
The kinetic energy depends on both the mass and the velocity of the object. The object with the least kinetic energy will have the lowest mass and/or the lowest velocity.
Now, let's compare the given options:
1. 100 grams of water falling at 10 m/s
Kinetic energy = 1/2 * 0.1 kg * (10 m/s)^2 = 5 J (joules)
2. 10 grams of dirt falling at 2 m/s
Kinetic energy = 1/2 * 0.01 kg * (2 m/s)^2 = 0.02 J
3. 10 grams of water falling at 1 m/s
Kinetic energy = 1/2 * 0.01 kg * (1 m/s)^2 = 0.005 J
4. 100 grams of dirt falling at 15 m/s
Kinetic energy = 1/2 * 0.1 kg * (15 m/s)^2 = 11.25 J
Comparing the results, we can see that the object with the least kinetic energy when it collides with the ground is:
10 grams of water falling at 1 m/s, with a kinetic energy of 0.005 J.
To determine the object that will result in the least kinetic energy when it collides with the ground, we need to calculate the kinetic energy for each object.
The formula to calculate kinetic energy is:
Kinetic energy = 0.5 x mass x velocity^2
Let's calculate the kinetic energy for each option:
1. 100 grams of water falling at 10 m/s:
Mass = 100 grams = 0.1 kg
Velocity = 10 m/s
Kinetic energy = 0.5 x 0.1 kg x (10 m/s)^2 = 5 J
2. 10 grams of dirt falling at 2 m/s:
Mass = 10 grams = 0.01 kg
Velocity = 2 m/s
Kinetic energy = 0.5 x 0.01 kg x (2 m/s)^2 = 0.02 J
3. 10 grams of water falling at 1 m/s:
Mass = 10 grams = 0.01 kg
Velocity = 1 m/s
Kinetic energy = 0.5 x 0.01 kg x (1 m/s)^2 = 0.005 J
4. 100 grams of dirt falling at 15 m/s:
Mass = 100 grams = 0.1 kg
Velocity = 15 m/s
Kinetic energy = 0.5 x 0.1 kg x (15 m/s)^2 = 11.25 J
Based on these calculations, 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 with a kinetic energy of 0.005 J.