A 2- A ball vertically upward from the top of a building 30 m above the ground with initial velocity is equal 30 m/s . what is the velocity when the ball is at 15 m above the ground . ​

I'm thinking it's 2 you are asked to explain the earth's magnetic field. which is the best reply? 1. the earth's magnetic south is similar to the north pole of a magnet. 2. the earth's core has a strong magnetic charge similar to the south pole of a magnet. 3. the earth's geomagnetic south is similar to the south pole of a magnet. 4. the earth's magnetic charge is not centered at either pole; it varies based on location.

You have a resistor and a capacitor of unknown values. first, you charge the capacitor and discharge it through the resistor. by monitoring the capacitor voltage on an oscilloscope, you see that the voltage decays to half its initial value in 2.70 miss . you then use the resistor and capacitor to make a low-pass filter. what is the crossover frequency fc?

Ethanol has a heat of vaporization of 38.56 kj/mol and a normal boiling point of 78.4 c. what is the vapor pressure of ethanol at 14 c?