Which object would best be identified by a periodic doppler shift in a star's spectrum along with a dip in the stars light intensity?
a black hole
a nebula
a comment
a planet

An engineer decides to use a slightly weaker material rather than a stronger material, since she knows that the stronger material can break suddenly. this is an example of what? a choosing a material that will show warning before it fails b using composite materials that combine strength c using a material for multiple applications d using design techniques that increase efficiency and reduce cost

Drag each pressure unit with the corresponding number to describe standard atmospheric pressure

What mass of ca(oh)2 is needed to make 1250ml of a .75m solution?