Answer:
The energy conversions that occur when a grapefruit falls from a tree is;
Potential energy ---> kinetic energy ---> potential energy
Combustion reactions occur in the presence of oxygen gas- True
Energy is the ability to do work - True
A renewable energy source is one that is replaceable - True
Light energy is emitted by certain organisms such as fireflies and glow-worms - True
Sound energy cannot travel through air - False
Heat energy cannot travel through a liquid for example water - False
Explanation:
According to the first law of thermodynamics, energy can not be created nor destroyed but is converted from one form to another. When a grapefruit falls from a tree, the energy conversion is as follows;
Potential energy ---> kinetic energy ---> potential energy
Combustion reaction refers to a reaction where a substance is burnt in oxygen to produce heat and light.
Energy is defined in science as the ability to do work. Renewable energy can be replaced. A typical example is solar energy.
Light energy is emitted by certain organisms such as fireflies and glow-worms.
Sound is a mechanical wave hence it must be transmitted through a medium. The medium through which sound waves are transmitted is air.
Heat travels through any thermal conductor. Water is an example of a good thermal conductor. Heat indeed travels through different liquids.
