To solve the problem, we must use the ideal gas law in its simplified form under different conditions known as Gay-Lussac's law, which relates pressure and temperature for a gas at constant volume: P₁/T₁ = P₂/T₂. Here, pressures (P₁ and P₂) are measured in psi, and temperatures (T₁ and T₂) must be in Kelvin.
Step 1: Convert the initial temperature from Celsius to Kelvin.
T₁ = 27°C + 273.15 = 300.15 K
Step 2: Set the known pressures and temperatures in the formula.
P₁ = 35 psi, P₂ = 40 psi, T₁ = 300.15 K
Step 3: Solve for the temperature at which the tyre bursts (T₂).
Rearranging the formula gives: T₂ = (P₂ × T₁) / P₁
T₂ = (40 psi × 300.15 K) / 35 psi
T₂ = 343.03 K
Step 4: Convert final T₂ back to Celsius.
T₂ = 343.03 K - 273.15 = 69.88°C
Therefore, the temperature at which the car tyre will burst is approximately 70°C. This value falls within the specified range of 70,70°C.