explain why more energy is expended by walking downstairs than by walking horizontally on the same spped.?

Answer 1

When you're walking downstairs, you are doing work against gravity. Gravity is pulling you down, so you have to constantly keep yourself up.

Gravity only works in the vertical direction, however. So, when you walk horizontally across the room, you do no work against gravity. Since you're not changing your distance up or down, gravity is not affecting you.

And the speed does matter! Remember, speed is essentially kinetic energy. The energy I was mentioning above is potential energy. That and the fact that how fast you move your body determines how much energy you use in moving your muscles. If the speed is the same in each case, the difference in the energy used to move your legs in each case is negligible.

Answer 2

From a physics viewpoint, walking downstairs uses less energy than horizontal walking; also from the physics the speed doesn't matter either. However, walking involves moving parts of the body, and it is possible that more muscles are exercised going downstairs than walking horizontally.

Answer 3

Perhaps walking downstairs expends both potential and kinetic energy while walking horizontally expends only kinetic energy, if that is what you are referring to.

Answer 4

more energy is expended by walking downstairs because the gravitat ional force does not match by walking downstairs remember the newtons 3rd law

Answer 5

i think its cos when ur walking down, gravity increases the force that you have to endure on your feet. if you can follow my train of thought... :P