Question

what is the difference in kinetic energy between a \\(0.644\text{ kg}\\) squirrel running \\(5.81\text{ m/s}\\) and a \\(0.235\text{ kg}\\) bird flying at \\(7.94\text{ m/s}\\)?

\\(\text{ke} = ?\text{ j}\\)

Explanation:

⚡ Using what you learned: kinetic energy and the work-energy theorem

Step 1: Calculate the kinetic energy of the squirrel

$$ KE_{\text{squirrel}} = \frac{1}{2} m_1 v_1^2 $$

$$ KE_{\text{squirrel}} = \frac{1}{2} (0.644\text{ kg}) (5.81\text{ m/s})^2 \approx 10.870\text{ J} $$

Step 2: Calculate the kinetic energy of the bird

$$ KE_{\text{bird}} = \frac{1}{2} m_2 v_2^2 $$

$$ KE_{\text{bird}} = \frac{1}{2} (0.235\text{ kg}) (7.94\text{ m/s})^2 \approx 7.408\text{ J} $$

Step 3: Find the difference in kinetic energy

$$ \Delta KE = KE_{\text{squirrel}} - KE_{\text{bird}} $$

$$ \Delta KE = 10.870\text{ J} - 7.408\text{ J} \approx 3.46\text{ J} $$

Answer:

3.46