A girl drops a ball of mass 0.40 kg0.40\text{ kg}0.40 kg. The ball falls a distance of 1.5 m1.5\text{ m}1.5 m to the ground. Ignore air resistance throughout this question. Take the acceleration of free fall ggg to be 10 m/s210\text{ m/s}^210 m/s2.
Calculate the decrease in gravitational potential energy of the ball as it falls through the 1.5 m1.5\text{ m}1.5 m.
The ball bounces off the floor and only rises to a maximum height of 0.90 m0.90\text{ m}0.90 m.
(i) Calculate the energy lost during the bounce.
Suggest one reason why energy is lost during the bounce.
On another occasion, the girl throws the ball straight down from a height of 1.5 m1.5\text{ m}1.5 m, giving it an initial kinetic energy of 12.0 J12.0\text{ J}12.0 J. Calculate the speed at which the ball hits the ground.
533 exam-style questions on CIE IGCSE Physics 1.7 Energy, work and power, covering 1.7.1a Energy stores and energy transfers, 1.7.1b Conservation of energy, 1.7.1c Kinetic and gravitational potential energy, 1.7.2 Work done, 1.7.3 Energy resources, 1.7.3a Energy resources and electricity generation, 1.7.3b Nuclear fusion as an energy source, 1.7.3c Efficiency of energy transfer, and 1.7.4 Power. Each one has a worked solution and a mark scheme showing where the marks go.