For approximately how long has life existed on the surface of the earth visible without a microscope

There are two iron rods, labeled A and B. When you touch A to a paperclip and lift up, the paperclip sticks to A. When you touch B to a paperclip and lift up, the paperclip does not move.

A sled is at rest at the top of a 2 m high slope. The sled has a mass of 45 kg. The sled's potential energy is J. (Formula: PE = mgh)

How high was a brick dropped from if if falls in 2.5 seconds?

As the temperature decreases, the atoms lose energy. The atoms begin to move slower. They are held together by attractive forces, but are still able to slide past each other.

What is the current when the voltage is 18 volts and the resistance is 6 ohms? 108 amps 12 amps 24 amps 3 amps

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

A sound that's produced by a single wave at a constant frequency and with no overtones is called

Which of the following is ignored when determining the relative mass of atoms? protons nucleus electrons. neutrons