State what is meant by the principle of conservation of energy.
An athlete throws a heavy medicine ball.
State the energy changes that take place from when the athlete begins to exert a force on the ball until the ball hits the ground and stops moving.
An athlete throws a heavy medicine ball.
The mass of the medicine ball is 5.0 kg5.0\text{ kg}5.0 kg. The athlete exerts a force on the ball for 0.50 s0.50\text{ s}0.50 s. The speed of the ball increases from 0 m/s0\text{ m/s}0 m/s to 14 m/s14\text{ m/s}14 m/s before it leaves the athlete's hands.
Calculate the momentum of the ball as it leaves the athlete's hands.
An athlete throws a heavy medicine ball.
The mass of the medicine ball is 5.0 kg5.0\text{ kg}5.0 kg. The athlete exerts a force on the ball for 0.50 s0.50\text{ s}0.50 s. The speed of the ball increases from 0 m/s0\text{ m/s}0 m/s to 14 m/s14\text{ m/s}14 m/s before it leaves the athlete's hands.
Calculate the average resultant force exerted on the ball.
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.