NEED HELP ASAP, WILL GIVE BRAINLIEST Which is an example of convection currents?

marshmallows toasting over a campfire
a pot being heated by an electric burner
feet getting hot when stepping across sand
a radiator emitting warm air and drawing in cool air

Space vehicles traveling through earth's radiation belts can intercept a significant number of electrons. the resulting charge buildup can damage electronic components and disrupt operations. suppose a spherical metallic satellite 1.3 m in diameter accumulates 3.0 µc of charge in one orbital revolution. (a) find the resulting surface charge density. (b) calculate the magnitude of the electric field just outside the surface of the satellite, due to the surface charge.

Which of the following situations is impossible? a) an object has velocity directed east and acceleration directed east. b) an object has zero velocity but non-zero acceleration. c) an object has constant non-zero velocity and changing acceleration. d) an object has velocity directed east and acceleration directed west. e) an object has constant non-zero acceleration and changing velocity.

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