which kinds of stars could have a black hole as a companion? select all that apply.
a. neutron
b. red giant
c. white dwarf
d. main sequence

Asmall 21 kilogram canoe is floating downriver at a speed of 1 m/s. what is the canoe's kinetic energy?

4. if you were an astronaut on the moon, what would you experience? what would you see from your perspective?

Two point charges are separated by a certain distance. how does the strength of the electric field produced by the first charge, at the position of the second charge, change if the second charge is doubled? a. the field does not change b. the field strength decreases by half. c. the field strength doubles d. the field strength quadruples