passwella.
Menu

Unilorin Post-UTME Physics 2022 (Model questions) Question 1

Question 1

Quantity of Heat

A waterfall is 42m high, calculate the difference in temperature of the water between the top and bottom of the waterfall assuming no heat is lost. [specific heat capacity of water = 4.20 × 103Jkg−1K−1, g = 10m/s2]

  1. A.1.0°C
  2. B.42.0°C
  3. C.4.2°C
  4. D.0.1°C
Show the answer and explanation

Answer: D (0.1°C)

Explanation

Potential energy becomes heat: mgh = mcΔθ, so Δθ = gh/c = 10 × 42 ÷ 4200 = 0.1°C.