Tyana is using lead balls to perform investigations of kinetic energy. She records her observations in two tables.



INVESTIGATION 1:  constant mass
Trial Velocity (meters/second) Mass (kilograms) Kinetic Energy (joules)
1 8 3 96
2 2 3 6
3 4 3 24
4 6 3 54


INVESTIGATION 2: constant velocity
Trial Velocity (meters/second) Mass (kilograms) Kinetic Energy (joules)
1 2 6 12
2 2 2 4
3 2 5 10
4 2 8 16

Using the patterns observed in Tyana's data, which two graphs best represent the relationships between velocity, mass, and kinetic energy?

A.
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B.
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C.
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D.
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1 answer

To answer your question effectively, we first need to analyze the data provided in both investigations to understand the relationships between velocity, mass, and kinetic energy.

Investigation 1: Constant Mass

Using the formula for kinetic energy (KE), which is: \[ KE = \frac{1}{2} m v^2 \] Where:

  • \( KE \) = kinetic energy in joules
  • \( m \) = mass in kilograms
  • \( v \) = velocity in meters/second

For the constant mass of 3 kg in Investigation 1:

  1. Trial 1: \( KE = \frac{1}{2} (3)(8^2) = 96 \) joules
  2. Trial 2: \( KE = \frac{1}{2} (3)(2^2) = 6 \) joules
  3. Trial 3: \( KE = \frac{1}{2} (3)(4^2) = 24 \) joules
  4. Trial 4: \( KE = \frac{1}{2} (3)(6^2) = 54 \) joules

The kinetic energy increases with the square of velocity, meaning it shows a parabolic relationship vs. velocity.

Investigation 2: Constant Velocity

Here, the velocity remains constant (2 m/s), while mass varies:

  1. Trial 1: For 6 kg, \( KE = \frac{1}{2} (6)(2^2) = 12 \) joules
  2. Trial 2: For 2 kg, \( KE = \frac{1}{2} (2)(2^2) = 4 \) joules
  3. Trial 3: For 5 kg, \( KE = \frac{1}{2} (5)(2^2) = 10 \) joules
  4. Trial 4: For 8 kg, \( KE = \frac{1}{2} (8)(2^2) = 16 \) joules

In this case, kinetic energy increases linearly with mass since the velocity is constant.

Summary of Relationships:

  • In the first investigation, kinetic energy is a function of the square of velocity (quadratic relationship).
  • In the second investigation, kinetic energy is a linear function of mass.

Graph Selection:

To select the appropriate graphs, you would be looking for:

  1. A parabola for Investigation 1 (KE vs. Velocity) showing KE increases quadratically with velocity.
  2. A straight line for Investigation 2 (KE vs. Mass) indicating KE increases linearly as mass increases.

Without seeing the actual graphs A, B, C, and D, I cannot definitively choose which two best represent these relationships, but these principles should help you identify them based on the characteristics we discussed. Look for one graph that has a parabolic shape for the KE vs. Velocity (Investigation 1) and another that has a straight line for the KE vs. Mass (Investigation 2).