Order-of-magnitude estimates for physical properties Steps:

• Recall typical values: kettle power ~10^3 W, pool volume ~10^3–10^5 m³, lorry momentum ~10^5 Ns, horse weight ~10^3 N.
• Compare each estimate to typical ranges using scientific notation.
• Verify A matches 2 × 10^3 W for kettle.
• Verify B, C match approximate scales; D exceeds horse weight by an order of magnitude.

Why D is correct:

• Weight W = mg with m ≈ 500 kg for a racehorse and g ≈ 10 m/s² gives W ≈ 5 × 10^3 N; 6 × 10^4 N implies m ≈ 6000 kg, too massive for a horse.

Why the others are wrong:

• A: Matches typical 2 × 10^3 W dissipation in a kettle heating element.
• B: Reasonable for a large municipal swimming pool holding ~2 × 10^5 m³.
• C: Aligns with lorry momentum m v ≈ 10^4 kg × 50 m/s = 5 × 10^5 Ns.

Final answer: D