A chemical change in a reaction of acids and bases can be indicated by a change in ... color? Size? Shape? Volume?

What type of simple machine is a catapult? (incline plane, lever, pulley, screw, wedge, or a wheel and axle) How do you know?

Where should the property "little voltage loss across long distances" be placed in the Venn Diagram? A) direct current B) alternating current C) both alternating and direct current D) neither alternating nor direct current

If you hear a higher pitch from a clarinet than from a saxophone, how do the frequencies of the sound waves from the clarinet compare to those of the saxophone? A - The saxophone's waves have a higher frequency than the clarinet.

An object with a mass of 5.0 kg is accelerating toward the surface of Earth at a rate of 9.8 m/s^2 Which change would double the gravitational force acting between the object and Earth? A. doubling the mass of the object B.

Commercial airplanes are sometimes pushed out of the passenger loading area by a tractor. An 1800-kg tractor exerts a force of 1.75*10^4N backward on the pavement, and the system experiences forces resisting motion that total 2400 N.

Why did scientists choose carbon as a base for the atomic mass unit? Which isotope of carbon did they use?

What organelle is found in all animal cells and some plant cells

Basic of Archimedes's principle of how fluid can make body to float and sink.

A bullet is accelerated down the barrel of a gun by hot gases produced in the combustion of gun powder. What is the average force (in N) exerted on a 0.0500 kg bullet to accelerate it to a speed of 625 m/s in a time of 1.10 ms (milliseconds)

Your boss at the Cut-Rate Cuckoo Clock Company wants to save money on materials. You are asked to reduce the balance wheel, which is cylindrical, dimensions to one-third their original values.