Kinetic energy uses KE = ½mv² formula

Steps:

• Assume typical car mass m ≈ 1000 kg.
• Speed v = 30 m/s, so v² = 900 m²/s².
• Compute ½ × 1000 × 900 = 450,000 J.
• Round to order of magnitude: 4.5 × 10^5 J ≈ 10^6 J.

Why C is correct:

• KE = ½mv² with m ≈ 1000 kg and v = 30 m/s yields ≈ 4.5 × 10^5 J, matching 10^6 J order of magnitude.

Why the others are wrong:

• A: 10^2 J is kinetic energy of a small object like a thrown ball, not a car.
• B: 10^4 J underestimates by factor of 100, ignoring car's mass.
• D: 10^8 J overestimates, as if car mass were 100,000 kg or speed 300 m/s.

Final answer: C