Which best explains why scientific theories grow stronger over time?

The spring constant, k, for a 22cm spring is 50N/m. A force is used to stretch the spring and when it is measured again it is 32cm long. Work out the size of this force.

What is a planetary nebula? Rings of icy rock which form around stars prior to fusion beginning. The remains of a high-mass star that has exploded. Interstellar gas from which planets are likely to form.

Which units can be used to measure length or distance? Check all that apply. gram meter kilometer liter inch Kilometer

The number of protons in the nucleus of an atom determines the species of the atom, i. e., the element to which the atom belongs. An atom has the same number of protons and neutrons. But the electron number cannot be used instead because A.

Which of the following represents the velocity of a moving object? B. 40 m north A. 40 C. 40 m/s D. 40m/s north

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

Gamma radiation can be significantly reduced by ... A sheet of paper Air A 3 mm thickness of aluminium Several cm of lead