Which is an example of velocity? a. a pickup driving 30 km in 20 minutes b. a car slowing down on a sharp curve c. an airplane traveling 450 km/h d. an 18 wheeler driving west at 50 km/h plz

What is the weight of a feather (mass = 0.0001 kg) that floats through earth's and the moon's atmospheres?

(a) if the pressure in gas is doubled while its volume is held constant, by what factor do (i) vrms and (ii) change? (b) is it possible to boil water at room temperature (20oc) without heating it? explain.

Four point charges each having charge q are located at the corners of a square having sides of length a. find symbolic expressions for the following. (a) the total electric potential at the center of the square due to the four charges (use any variable or symbol stated above along with the following as necessary: ke.) vtotal= (b) the work required to bring a fifth charge p from infinity to the center of the square (use any variable or symbol stated above along with the following as necessary: w=