Energy from the Sun evaporates water from the sea. Some of this water eventually drives a hydroelectric power station. Give an account of the physical processes and energy changes involved.
In a hydroelectric power station, 2.5×105 kg2.5 \times 10^5\text{ kg}2.5×105 kg of water per second fall through a vertical distance of 150 m150\text{ m}150 m. The water passes through turbines to generate electricity, and leaves the turbines with a speed of 16 m/s16\text{ m/s}16 m/s.
Calculate the gravitational potential energy lost by the water in 1 second. Use g=10 m/s2g = 10\text{ m/s}^2g=10 m/s2.
Calculate the kinetic energy of the water leaving the turbines in 1 second.
229 exam-style questions on CIE IGCSE Physics 1.7.1a Energy stores and energy transfers. Each one has a worked solution and a mark scheme showing where the marks go.