Question

a roller coaster car sits on top of a hill with 40 j of potential energy. as it goes down the hill, it has 15 j of potential energy, 20 j of kinetic energy, and some thermal energy. how much thermal energy is present?

Explanation:

Step1: Apply the law of conservation of energy

The total initial energy \(E_{initial}=E_{p - initial}=40\,\text{J}\). The total final energy \(E_{final}=E_{p - final}+E_{k}+E_{thermal}\). According to the law of conservation of energy \(E_{initial} = E_{final}\).

Step2: Solve for \(E_{thermal}\)

Substitute the values into the equation \(40=15 + 20+E_{thermal}\). Then \(E_{thermal}=40-(15 + 20)\).

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Answer:

5 J