Mechanical energy is conserved in the presence of which of the following types of forces select all that apply. a) frictional b) magnetic c) electrostatic d) gravitational

c) electrostatic

d) gravitational

Explanation:

Mechanical energy remains constant (conserved) if only conservative forces act on the particles.  

In this sense, the following forces are conservative:  

-Gravitational  

-Elastic

-Electrostatic

While the Friction Force and the Magnetic Force are not conservative.  

According to this, mechanical energy is conserved in the presence of electrostatic and gravitational forces.

Therefore the correct options are C and D.

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no. bullets are macro objects. wave nature is for light waves, extremely tiny particles. if a light particle was the size of your finger, the bullet would be the size of the universe. so basically, that huge difference in size makes the wave nature of matter insignificant.