A ball is thrown horizontally at 15 m/s from the top of a building 20 m tall. Ignoring air resistance, what is its SPEED just before it hits the ground?

Which scientist is most closely associated with natural selection?        

Which characteristic is most useful for identifying a eukaryotic cell?        

A ball is thrown straight upward at 12.0 m/s from a balcony 25.0 m above the ground. It misses the balcony on the way down and lands on the ground. Ignore air resistance. What is the ball’s maximum height above the GROUND, in meters?

A small positive charge is released from rest in an electrostatic field, and only electric forces act on it. Select ALL statements that are true.

Use k = 8.99 × e+9 N·m²/C², ε₀ = 8.85 × e-12 C²/(N·m²), e = 1.60 × e-19 C. Three point charges are fixed in place: +[a] μC at the origin, −[b] μC at ([x] m, 0), and +[c] μC at (0, [y] m). What is the magnitude of the net electric force on the +[a] μC charge, in N? Q10_formula_figure.png

Two identical small metal spheres carry +8.0 nC and −2.0 nC. They are touched together and then separated. What is the charge on each sphere afterward?

A very large insulating sheet carries a uniform surface charge density of +6.00 nC/m². Without calculating, how does the electric potential change as you move directly away from the sheet, and why?

Charges +q, +q, and −q sit at the three corners of an equilateral triangle. What is the direction of the net electric field at the center of the triangle? Q04_figure.png

In a certain region the electric potential is V(x) = 5x² − 3x, with V in volts and x in meters. What is the x component of the electric field at x = 2.0 m?