The geologic time scale is broken up into time units of different sizes based on
A) eons, eras, periods, and epochs.
B) changes in fossilization.
C) visible and nonvisible life forms.
D) major changes in life forms.
Answer: D
You might also like to view...
?Two flat rectangular mirrors are set edge to edge and placed perpendicular to a flat nonreflecting surface. A light ray that reflects from mirror 1 at angle?M1 then strikes the second mirror and reflects at?M 2 such that the angle between the ray reaching mirror 1 and the ray leaving mirror 2 is 180°. The angle between the two mirrors is
A. ?0°. B. ?45°. C. ?90°. D. ?150°. E. ?235°.
An apparent westward motion of a planet in the sky compared to the background stars (as viewed from Earth) when observed on successive nights is referred to as
a. epicycle. b. retrograde motion. c. prograde motion. d. heliocentric motion. e. deferent.
Nitrogen at 30°C and atmospheric pressure enter a triangular duct 0.02 m on each side at a rate of 4 × 10–4 kg/s. If the duct temperature is uniform at 200°C, estimate the bulk temperature of the nitrogen 2 m and 5 m from the inlet.
GIVEN
• Atmospheric nitrogen flowing through a triangular duct
• Bulk inlet temperature (Tb,in) = 30°C
• Width of each side of the duct (w) = 0.02 m
• Mass flow rate (m ) = 4 × 1–4 kg/s
• Duct temperature (Ts) = 200°C (uniform)
FIND
• The bulk temperature
(a) 2 m from the inlet and,
(b) 5 m from the inlet
SKETCH
Why is Mars' surface red?
a) because little green men painted it that way b) because its surface is mostly made of lava ejected from its giant volcanos c) because there is more ammonia than methane on the surface of Mars, unlike on the Jovianplanets Uranus and Neptune d) because the soil is iron rich and the iron reacted with oxygen in the early atmosphereto make rust e) because the carbon dioxide rain strikes the surface and reacts