Can a star turn into a planet? Can gravity form waves?

Does every black hole contain a singularity?

Does the influence of gravity extend out forever?

Galaxies look stationary, so why do scientists say that they rotate?

Have aliens ever visited earth?​

There are two-speed cameras, one in an are where the speed limit is 30 km/h and another where the speed limit is 50 km/h. in which will there be a smaller time interval between the photographs? explain your answer.

What’s #16 asking and how do i solve it?

Large electric fields in cell membranes cause ions to move through the cell wall. the field strength in a typical membrane is 1.0 x 10 7 n/c. what is the magnitude of the force on a calcium ion with charge +e? what is its acceleration? is it possible for a particle with the same charge as as calcium to have a different acceleration if placed at this location? what would change the acceleration: mass of the particle? diameter of the particle?