Which speed is at the sound barrier?

5 m/s

257 m/s

3.0 x 10⁸ m/s

343 m/s

The model below shows a calcium atom. How many electrons are in the third energy level? 2 8 18 20

reddit One company sells a defibrillator for home use that uses a 9-volt DC battery. The battery is rated at 4.2 A•hr (amp•hour). Roughly how much charge can the battery deliver?

What is not a wave of the eletromagnetic spectrum

At which position does the diver have the most gravitational potential energy

given the perimeter of a rectangle and either the length or width, find the unknown measurement using the appropriate formula. The perimeter is 54cm, and the length is 15cm.

A car accelerates uniformly from 0 to 15m/s in 5 s. Calculate acceleration.

Which device would a sleep researcher use to monitor a sleeping person's brain waves?

An experiment is performed to obtain the value of a physical property. If the true (i. e., correct) value of the property is 50 and the measured (i. e., experimental) value is 32, the percent error of the experimental result is:

White moths were found in huge numbers in the city of Birmingham. These moths could be easily camouflaged by the trees. Because of sudden industrial development, the trees in the city were covered with soot.

What two factors determine how fast weathering occurs