Which requires more work, lifting a 20 kg box vertically 2 meters OR lifting a 10 kg box 4 meters? Explain.

I'm not sure in which direction 10kg is lifted but assuming 10kg is lifted (or dragged) horizontally then

the 20kg vertically requires more work because gravity pushing down on it will require a somewhat large output of Energy.

But if they are both lifted vertically (or horizontally)then they are equal in work.

Hope this helps

the bal will not change its velocity.

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.