Asurvey team is trying to estimate the height of a mountain above a level plain. from one point on the plain, they observe that the angle of elevation to the top of the mountain is 28 ∘ . from a point 1000 feet closer to the mountain along the plain, they find that the angle of elevation is 30 ∘ .

The heliocentric and the geocentric models of the solar system included these central principles

When electrons are added to the outermost shell of a carbon atom, it forms--an anion that has a larger anion that has a smaller cation that has a larger cation that has a smaller radius.

Aresistor with an unknown resistance is connected in parallel to a 9 ω resistor. when both resistors are connected in parallel to an emf source of 21 v, the current through the unknown resistor is measured with an ammeter to be 4 a. what is the resistance of the unknown resistor? answer in units of ω.