A sound system is designed to produce a 1.0W/m2 sound intensity over the surface of a hemisphere 20 m in radius. What acoustic power is needed from an array of speakers at the center of the sphere?

What refers to the time it takes for a spacecraft to complete one orbit? a. orbital decay b. orbital height c. orbital period d. orbital velocity

Steve and Carl are driving from Scranton to Bridgeport, a distance of 180 miles. If their speed averages 60 miles an hour, how long will it take them to get there

Which of these would have a volume equal to about 2 cm³? A. 2 grains of rice B. a pair of turtle doves C. 2 African elephants D. a pair of dice from a board game

Which of the following is not in our solar system star black hole asteroid comet

A DC-9 aircraft leaves an airport from a runway whose bearing is N4343degrees°E. After flying for one half 1 2 mile, the pilot requests permission to turn 90degrees° and head toward the southeast. The permission is granted.

How do whales bats and dolphins use echolocation? A To scare away predators B To attract mates C To orient them selves and find food D To tell animals of there species where they are

How much force would be needed to move a car with the mass of 100kg to an acceleration of 5m/s/s?

A pendulum bob is made from a sphere filled with water. What would happen to the frequency of vibration of this pendulum if the sphere had a hole in it that allowed the water to leak out slowly?

Elias serves a volleyball at a velocity of 16 m/s. The mass of the volleyball is 0.27 kg. What is the height of the volleyball above the gym floor when its total mechanical energy is 41.70 J? Round to the nearest number.

Which of the following is the best description of a graph? A. Equations that can be plotted B. A representation of an equation C. Independent and dependent variables D. x and y lines