Two trains start a journey at the same time 120 miles apart, travelling towards each other. The first train is travelling at 60 mph and the second train is travelling at 40 mph. How long does it take for the two trains to meet?

Electrons are much larger than protons and neutrons. True False

Which principle explains how fiber optics can transmit data in the form of light pulses over large distances with little loss in signal strength? total internal reflection the index of refraction the index of reflection total internal refraction

In hooke's law is force directly proportional to extension?

A system absorbs 186 kj of heat and the surroundings do 110 kj of work on the system. what is the change in internal energy of the system? express the internal energy in kilojoules to three significant figures.

How does the electrical potential energy between two positively charged particles change if the distance is increased by a factor of 2? a. it is reduced by a factor of 2 b. it is increased by a factor of 2 c. it is increased by a factor of 4 d.

Which concept was supported by taking measurements of the same stars at night and then again during solar eclipses?

Which of these is a biotic factor? A) topography B) soil C) air D) bacteria

One reason it's often easy to miss and action reaction pair is because of?

Recently, some information about a distant planet was learned. It has a radius of 6000000 meters, and the density of the atmosphere as a function of the height h (in meters) above the surface of the planet is given by δ (h) =

Which of the following is not a good approximation of the relationship between independent and dependent variables? A. independent: first, dependent: next B. independent: input, dependent: output C. independent: cause, dependent: effect D.