Answer:
B. holding a coffee mug
Explanation:
Something must move a distance for work to be done.
No. Mechanical energy is not conserved. There's quite a bit of friction on the slide. So some of the potential energy is lost to heat on the way down, and the child arrives at the bottom with hot pants and less kinetic energy than you might expect.
The movements of the tectonic plates
Answer: Smoking cigarettes
Explanation: The other options don't cause pollution to form in the air besides smoking, from the particles it creates causing harm and damage to your lungs and fill the air with smoke particles.