It takes 4200 Joules to heat up 1 kg of water by 1 C^o. If you have a kettle with a power of 2500 Watts, how long will it takes to boil 0.8 kg of water from an initial temperature of 25 C^o to the nearest second??
Energy required calculated using the equation for specific heat capacity: mcdT = dE where m is mass, c is specific heat capacity and dT is the change in temperature.
Time taken is calculated using the relation between energy, power and time: E / P = t. Substituting in from the previous equation: m * c * dT / P = t. Finally substituting in the numbers: 0.8 * 4200 * (100-25) / 2500 = 100.8 seconds.
Answer: 101 seconds.
BC
Related Physics GCSE answers
All answers ▸Why do lasers produce an intense coherent beam of light?
Explain the difference between a real and a virtual image.
Write the equations of motion for constant acceleration and describe each term involved. Explain how to apply these equations of motion to calculate the horizontal and vertical components of a projectile moving under the force of gravity only.
Coal is a non-renewable energy resource. Name two other non-renewable energy resources.