Which of these questions is a scientific question about skateboarding?
a how fast does a skateboard move at the bottom of a ramp?
b. which color of wheel looks best?
c. should skateboarding be allowed in shopping malls?
d. what is the best trick to do while moving backward?

A How fast does a skateboard move at the bottom of a ramp?

Explanation:

How fast does a skateboard move at the bottom of a ramp is a scientific question about skateboarding.

'A' is the only one that can be tested and measured.

'B' and 'D' ask for 'best'. 'C' asks 'should'. These are things that can't be measured, and they're individual opinions anyway.

explanation:

earth's surface is mainly heated by the absorption of infrared radiation from the sun.

evaporation occurs because molecules in liquid water are warmed ( usually by the sun) and vibrate quicker, becoming less dense and rise.

condensation occurs because molecules in water vapor are cooled and therefore vibrate more slowly thus becoming more dense and eventually fall to earth.

lines of equal barometric pressure on a weather map are called: isobars : lines of equal temp on a weather map are called: isotherms.​