Question

question 2 (1 point)
a ball drops some distance and loses 30 j of gravitational potential energy. do not ignore air resistance. how much kinetic energy did the ball gain?
more than 30 j
exactly 30 j
less than 30 j
cannot be determined from the information given

Explanation:

Step1: Recall Energy Conservation with Air Resistance

When a ball drops, gravitational potential energy (GPE) is converted. But air resistance does work (dissipates energy as heat/sound). So the GPE lost ($30\ \text{J}$) is split into kinetic energy (KE) gained and energy lost to air resistance.

Step2: Analyze Energy Transfer

Let $ \Delta \text{GPE} = 30\ \text{J} $ (lost), $ \Delta \text{KE} $ (gained), and $ E_{\text{air}} $ (energy lost to air resistance, $ E_{\text{air}} > 0 $). By energy conservation: $ \Delta \text{GPE} = \Delta \text{KE} + E_{\text{air}} $. Rearranging: $ \Delta \text{KE} = \Delta \text{GPE} - E_{\text{air}} $. Since $ E_{\text{air}} > 0 $, $ \Delta \text{KE} < 30\ \text{J} $.

Answer:

less than 30 J