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.

a. They are typically operated at lower temperatures.

a. They are typically operated at lower temperatures.b. They are especially helpful for viewing cool or obscured astronomical objects.

waves moving from a fast medium to a slow medium will experience a reflection as light travels more slowly than red light. total internal reflection occurs when the critical angle is.

answer; equivalent to a one(1) horsepower motor;