Which of the following best describes unstable equilibrium?

Weather is atmospheric conditions at a specific time and place (todays rain). Climate is average weather conditions over long periods (tropical climate). Weather changes daily; climate changes over decades or centuries.

Elements of weather: temperature, rainfall, humidity, wind speed and direction, air pressure, sunshine. Instruments: thermometer, rain gauge, hygrometer, anemometer, barometer.

Factors affecting climate: latitude (distance from equator), altitude, distance from sea, ocean currents, prevailing winds. Nigeria tropical climate but varied from coastal to northern regions.