This is a machine consisting of two wheels of different sizes that rotate together. It is a modified lever.

1. A certain atom has 20 electrons, 21 neutrons, and 20 protons. What is the atomic mass of the atom?

Why is there more evaporation in the tropics?

Water evaporators is this a physical change or a chemical change?

In a light interference pattern, alternate dark and bright fringes are seen. Why are the bright fringes formed? a) no interference b) too much interference c) destructive interference d) constructive interference

Why is mathematics important to science?

Two uncharged metal spheres, #1 and #2, are mounted on insulating support rods. A third metal sphere, carrying a positive charge, is then placed near #2. Now a copper wire is momentarily connected between #1 and #2 and then removed.

Which waves can travel through a vacuum? A) light waves Eliminate B) ocean waves C) sound waves D) mechanical waves

Select the statement that best describes gravity. Gravity is the force that draws objects closer to the Earth because of the positive or negative charge.

A cylindrical metal rod is 2.40 m long and 5.99 mm in diameter. The resistance between its two ends (at 20oC) is 1.38 * 10-3 Ω. (a) What is the material? (b) A round disk, 2.24 cm in diameter and 1.20 mm thick, is formed of the same material.

Two cars are moving in the same direction in parallel lanes along a highway. At some instant, the velocity of car A exceeds the velocity of car B. Does that mean that the acceleration of car A is greater than that of car B? Explain.