Which of the following statements about infrared telescopes is NOT true? a. They are typically operated at lower temperatures.
b. They are especially helpful for viewing cool or obscured astronomical objects.
c. They were first built in the 1960s.
d. They are often placed on mountaintops.
e. They do not work well at high altitudes.

Ascrew incorporates which other simple machine? lever wheel and axle inclined plane pulley

Ryan is examining the energy of the particles in a bar of gold. what is ryan most likely studying?

Which statement best describes the superposition principle? a.) if two in-phase waves arrive simultaneously at a point, their amplitudes add up b.) if two out-of-phase waves arrive simultaneously at a point, their amplitudes add up c.) if two in-phase waves arrive at a point one after another, their amplitudes add up d.) if two out-of-phase waves arrive at a point one after another, their amplitudes adds up