Which of the following changes igneous or sedimentary rock into metamorphic rock?
a.
heat and pressure
b.
heat and weathering
c.
water and weathering
d.
water and pressure

Stars x and y are both bluish main sequence stars. star x has a higher absolute brightness than star y. how do the two stars compare? explain

The respiratory system removes oxygen and water from the body. select the best answer from the choices provided t f

The ratio of lift to drag l/d for a wing or airfoil is an important aerodynamic parameter, indeed, it is a direct measure of the aerodynamic efficiency of the wing. if a wing is pitched through a range of angle of attack, l/d first increases, then goes through a maximum, and then decreases. consider an infinite wing with an naca 2412 airfoil. estimate the maximum value of l/d. assume that the reynolds number is 9x10^6.