Why are all machines not 100% efficient

A. Mass

B. Gravity

C. Friction

D. Distance

When you paddle a canoe, you push the water backwards. What do you think will happen to the canoe? How is this related to the Third Law Of Motion?

A 4000-? resistor is connected across a 220-V power source. What current will flow through the resistor?

What is used to measure heat? change in temperature constant temperature constant specific heat change in specific heat

What is the name of moving fields of angular blocks which are formed by gravity and the freezing-thawing cycle? A. Scree B. Talus C. Bedrock slumps D. Bedrock slides E. Rock glaciers

What occurred during the Cenozoic era? A. a meteor impact B. the ice age C. dinosaur extinction D. plants and animals first colonize on land

A glass window is a clear object that light passes through as it travels in a straight line. This is a good example of A. refraction of light. B. transmission of light. C. absorption of light. D. reflection of light.

Why is net force a vector sum A. All forces have direction and magnitude B. Forces can only be attractive C. All forces are contact forces D. There are four fundamental forces

Does the elf owl's small size allow it to live in cacti

If grapefruit juice has a ph of 3.0 and egg white have a ph of 8.0, which contains more h + ions? how many more?

Consider a single photon with a wavelength of λ, a frequency of ν, and an energy of e. What is the wavelength,? Consider a single photon with a wavelength of λ, a frequency of ν, and an energy of e.