Answer: force of gravity on the body due to height difference above the earth's surface
Explanation: as you increase the height of a body above ground, you do work against gravity in moving it from a point on the earth's surface to that point. So a body falling has a stored up gravito-potential energy which acts on it downward due to its mass, accelerating it downwards
Answer b): kinetic energy of the body
Explanation: the downward force produces an acceleration of magnitude 9.81m/s2 downwards which means an increasing velocity. This increasing velocity means the kinetic energy of the body is increasing (kinetic energy is proportional to velocity of the body squared)
When the temperature lowers the plants can freeze and die. One way to prevent that is to cover the plants so they dont freeze
Duracell batteries are an example of an electrochemical cell that is powered between the reaction of Magnesium and Zinc, occurring in basic conditions (alkaline battery). This type of reaction has a precise output of 1.5 volts, and looks like this:
Zn + 2MnO2 ➡️ ZnO + Mn2O3
It’s not rechargeable.
Golf Cart Batteries are an example of an electrochemical cell that is powered by the reaction between Lead and Sulfuric Acid (Lead-Acid battery). This type of reaction occurs on larger scales than an alkaline battery, and thus can generate a variety of powers depending on how many instruments are present within the battery. The reaction looks like this:
PbO2 + Pb + 2H2SO4 ➡️ 2PbSO4 + H2O
This is a rechargeable cell, but is rather prone to discharging by the environment and surroundings of the battery.