how do scientists know that black holes exist A. by running experiments on the sun B. by observing objects and light around black holes C. by viewing black holes with powerful telescopes D. all of the above E. none of the above

If the rate of change of the magnetic field applied to a loop of wire is doubled, what happens to the induced emf in that loop assuming that all other parameters remain unchanged?

A girl lifts a 160 N load a height of 1 m in a time o. 5. what is power does the girl produce

What is the force which makes a 2000 kg vehicle accelerate by 3.2 meters per second squared?

Where could convection currents form? Check all that apply. in a sand dune in a freshwater lake in the atmosphere in outer space in Earth's mantle

After a long night of cramming for a test, your college room-mate hits his head forcefully against the wall of your room in despair. According to Newton's 3rd Law, as he exerts a force against the wall, there must be an equal and opposite force.

Hydroelectric power uses: wind water coal the sun

Two lightweight metal spheres are suspended near each other from insulating threads. One sphere has a net charge; the other sphere has no net charge. The spheres will: A. Attract each other B. Exert no electrostatic force on each other C.

Read the given list of organisms. squirrel, zebra, tortoise, rabbit, horse What best describes the role of these five organisms in a food web?

What are the SI units for specific heat capacity

What are starburst galaxies and what do they have to do with galaxy evolution?