When a switch is closed, completing an LR series circuit, the time needed for the current to reach three-quarters its maximum value is time constants. a.) 1.33b.) 1.38c.) 0.693d.) 0.500

the current is 0.6

voltage ÷ resistance = current

so 12 ÷ 20 = 0.6

this could be newton#'s law of cooling. the cooling curve is exponential

the aurora is formed when charged particles emitted from the sun during a solar flare penetrate the earth's magnetic shield and collide with atoms and molecules in our atmosphere. these collisions result in countless little bursts of light, called photons, which make up the aurora.

auroras are generated by charged solar particles hitting molecules in earth's atmosphere. this usually happens in high latitudes, because our planet’s magnetic field tends to funnel these particles toward the poles. that’s why it can be experienced in northern ohio.