How does hand sanitizer work?

U have to open the bottle and then squeeze a coin sized drop and then rub it both hands until it gets dried.

They can measure  the amount of energy gained or lost

Firstly, the water in the dams hold gravitational potential energy as they are above ground level. the gravitational potential energy is then transferred to kinetic energy as it falls, spinning the turbinethe turbine then spins the generator, which is a large magnet surrounded by metal coils. by doing this, the generator generates electricity. in this action, the energy transfer taken place is kinetic to electric energy