What does conservation of energy say? In addition to the definition, provide the mathematical equation.

A bucket begins holding 25 kgs of sand. The bucket is to be lifted to the top of a 20 meter tall building by a rope with density 0.3 kg/m. However, the bucket has a hole in it, and leaks 0.3 kgs of sand each meter it is lifted. Find the work done lifting the bucket and rope to the top of the building. Use 9.8 m/s² for gravity.

How much work does a supermarket checkout attendant do on a can of soup he pushes 0.580 m horizontally with a force of 4.90 N? Express your answer in joules and kilocalories. J kcal

Kangaroos have very stout tendons in their legs that can be used to store energy. When a kangaroo lands on its feet, the tendons stretch, transforming kinetic energy of motion to elastic potential energy. Much of this energy can be transformed back into kinetic energy as the kangaroo takes another hop. The kangaroo’s peculiar hopping gait is not very efficient at low speeds but is quite efficient at high speeds. as shown the energy cost of human and kangaroo locomotion. The graph shows oxygen uptake (in mL/s) per kg of body mass, allowing a direct comparison between the two species. For humans, the energy used per second (i.e., power) is proportional to the speed. That is, the human curve nearly passes through the origin, so running twice as fast takes approximately twice as much power. For a hopping kangaroo, the graph of energy use has only a very small slope. In other words, the energy used per second changes very little with speed. Going faster requires very little additional…

For exercise, an athlete lifts a barbell that weighs 400 N from the ground to a height of 2.00 m at a constant speed in a time of 1.60 s. a.) What is the output energy, in kJ (kiloJoule)? b.) What is the metabolic energy, in kJ (kiloJoule)? c.) How much thermal energy is created in this process, in kJ (kiloJoule)?

What can you do to increase the power you develop as you climb a flight of stairs?

A bird is flying through through the air... What forms of mechanical energy does this bird possess? (Select all that apply). Gravitational Potential Energy Elastic Potential Energy Electrical Energy Kinetic Energy Nuclear Energy

Read the text about an object in motion. A maple tree seed hung from a branch of a tall maple tree. A strong breeze blew the seed off the branch. The seed drifted down toward the ground and landed in a patch of dirt. The seed sat in the dirt for a week before starting to germinate. When was the least gravitational potential energy stored between the seed and Earth? Assume that the seed's mass did not change. when the seed was attached to the tall branch when the seed was blown off the branch by the wind when the seed was about to germinate in the dirt

Which of the following defines the relationship between potential energy (U) and work (W) for conservative systems? A. AU = 0 B. AU > 0 C. AU < 0 D. AU = -W E. AU = +W