Which is an example of negative acceleration?
a) a snowboarder who increases speed when traveling downhill
b) a biker who maintains a constant speed through a race
c) a skateboarder who reduces speed when moving up a hill
d) a runner who fluctuates speed by increasing and decreasing speed

Does the energy in a solid increase or decrease when changing to a liquid?

Achemical reaction (also known as a chemical change) produces substances that are chemically different from the starting materials. an example of a chemical reaction is the formation of water from hydrogen and oxygen gas.in a physical change, a substance changes its physical appearance but not its chemical identity. an example of physical change is the formation of liquid water from solid water, a familiar process called melting. physically, liquid water looks very different from solid water (ice) but the chemical identity, water, is the same for both. which of following changes that affect the composition of our atmosphere involve physical changes and which involve chemical reactions? oxygen gas changes to ozone during thunderstorms carbon dioxide is produced by the combustion of gasoline in an automobile engine. when coal, oil, and natural gas are decomposed in landsills they produce methane gas. freezing rain develops when a warm air mass overrides a cold air mass. fog forms from water vapor when the temperature drops below the dew point

Jose and eric were given four samples in lab. the results of their analysis are shown in the table. based on the data they collected, which sample is most likely a metal?