CDS Heat & Temperature

A large bucket of water at 30°C has more heat energy than a small cup of water at 80°C. 4. Specific Heat Capacity (s) — This is the amount of heat needed to raise the temperature of 1 kg of a substance by 1°C. Water has the highest specific heat = 4200 J/kg°C. This is why water is used as a coolant. 5

Conduction (solids), Convection (liquids and gases), Radiation (no medium needed — like sunlight). FORMULA BLOCK Heat Formula: Q = m × s × ΔT Where: Q = Heat energy (in Joules) m = Mass of substance (in kg) s = Specific heat capacity (in J/kg°C) ΔT = Change in temperature (Final Temp − Initial Temp) Temperature Conversion Formulas: °C to °F → F = (9/5 × C) + 32 °F to °C → C = 5/9 × (F − 32) °C to K → K = C + 273 K to °C → C = K − 273 Note: 0°C = 273 K = 32°F. Absolute Zero = 0 K = −273°C. EXAM PATTERNS RRB Group D commonly asks: - Direct conversion between Celsius, Fahrenheit, and Kelvin - Which method of heat transfer applies to a situation (sun heating earth = Radiation) - Specific heat of water based problems - Finding Q using the formula Q = msΔT - Comparing heat content vs temperature SHORTCUT / TRICK Trick 1 — Temperature Conversion Memory Aid: To convert Celsius to Fahrenheit, remember: Double it, subtract 10%, add 32

A large cold object can have MORE heat energy than a small hot object. Heat depends on mass AND specific heat AND temperature. Temperature alone does not decide heat content. Also, never forget to add 273 when converting °C to Kelvin — losing that step costs marks.