A squirrel drops an acorn onto the head of an unsuspecting dog. The acorn falls 4.0m before it lands on the dog. We can ignore air resistance. How many seconds did the acorn fall?

The ultraviolet light that causes suntans (and sunburns!) has a typical wavelength of 300 nm. what is the frequency of these rays?

One nanometer is equal to how many centimeters?

Which best describes what is made of matter? all living things and objects all atoms all solid objects and atoms all living things

If an object has a mass of 20 grams and a volume of 40 cm3, what is its density in g/cm3?

What part of the plant cell is responsible for making its food?

A man consumes 2245 kcal of food in one day, converting most of it to maintain body temperature. If he loses half this energy by evaporating water (through breathing and sweating), how many kilograms of water evaporate?

If an eagle and a bumblebee are traveling at 8km/hr which has more momentum?

For each case, identify the force (including its direction) that causes the acceleration. (a) A sprinter at the very start of the race.

Select the effects of radiation below that are stochastic: associated with short-term, high-level exposure associated with long-term, low-level exposure include cancer and other DNA mutation include burns and radiation sickness

On the modern periodic table, elements are ordered according to what?