What layer of the atmosphere returns radio and tv broadcasts back to earth?

When you open a switch in an electric circuit you are creating a gap and stopping the flow of electrons. O True O False

A moterbike accelerates 8m/s. What is the final velocity of the bike after 3 s?

How many years will pass on Earth while Saturn makes one revolution around the sun? 1 10 30 95

Explain why the helium gas inside this balloon exerts pressure on the balloon.

Voltage will be induced in a wire loop when a magnetic field within that loopa. is at right angles to the electric field b. changes c. aligns with the electric field d. converts to magnetic energy

A child pushes horizontally on a box of mass m which moves with constant speed v across a horizontal floor. The coefficient of friction between the box and the floor is μ. At what rate does the child do work on the box?

What two qauntities must be known to calculate the density of a sample of matter

An element's atomic number is 38. How many protons would an atom of this element have?

What's are some forms of chemical energy

True or false a liquid does not have a definite shape, but it does have a definite volume.