Well, energy can be produced from the burning of fossil fuels which produce steam to spin turbines which generates electricity. But fossil fuels like coal and oil are no renewable.
Some renewable ways to get energy is water where they separate hydrogen from h2o because hydrogen can be made into energy. Also nuclear fission is another way to get energy. That's when in a nuclear power plant, the atoms nucleus is split which sends a large amount of energy.
Wind energy is another source of energy, which is from windmills. Another renewable energy source is solar energy. That's when u use solar cells, like some houses and calculators have, which generates a lot of energy, but only in the day since the sun doesn't shine in the nigh.
Hope I helped!!!
by the formula of spring force we know that

here we know that


now we will have


now by similar way if the stretch in spring is 0.25 m
force is given by



so it will require F = 250 N force
No, energy transformation is occurring in every point of the motion.
In fact, the ball starts from point 1 with maximum kinetic energy and zero potential energy (taking the hand of the boy as reference level). The kinetic energy converts into gravitational potential energy as it goes higher: in point 2, part of the kinetic energy has converted into potential energy (because the velocity has decreased, while the height has increased), and then when the ball reaches point 3 all the kinetic energy has converted into potential energy (because now the velocity is zero, while the height is maximum). As the ball descends (point 4), the velocity starts to increase again, therefore the kinetic energy increases and the potential energy decreases (because the height is deacreasing now).
Summarizing, energy transformation is occuring in every point of the motion.