A train travels 90 kilometers in 1 hours, and then 60 kilometers in 3 hours. What is its average speed

How can electric shock be prevented?

How many moles of MgCl2 are there in 348 g of the compound?

When an electron in a hydrogen atom is in the n = 3 state, is it on average closer to, farther from, or the same distance to the nucleus than in the ground state?

Which best describes tropical continental climate during the summer? A. clear, dry weather, B. cloudy, wet weather, C. cold, dry weather, D. hot, dry weather

Problems with solar energy include

They are generally thought to be blank naturally occurring emotions that are present from birth

If an aircraft is loaded 90 pounds over maximum certificated gross weight and fuel (gasoline) is drained to bring the aircraft weight within limits, how much fuel should be drained?

3. Shortwave radio is broadcast between 3.50 and 29.7 MHz, To what range of wavelengths does this correspond? Why do you suppose this part of the spectrum is called shortwave radio?

How does a star's temperature change as the star ages from a main sequence star to a red giant and from a red giant to a white dwarf?

What factors in the atmosphere seem to have the greatest effect in the amount of radiation received from the sun?