20.4 years is 20.4/10.2 = 2 half-life cycles, which means a quarter of the starting mass or 15.2 g will remain after this time.
Dinosaurs but I need the whole groups yo tell you ;)
Not 100% sire but I think it'd be Yellow since we see red and green light together as Yellow
The way I look at these things is like this:
-- The runner covered 12 meters in 4 seconds.
Average speed = 3 meters per second.
-- Speed at the beginning = zero.
In order to make the average 3, Speed at the end = 6 meters per second.
-- Speed increased from zero to 6 meters per second in 4 seconds.
It must have increased 1.5 meters per second each second.
That's choice-#2.
90 degrees - 30 = 60 degrees
Velocity = (5m/s - 4.35m/s x cos(30)) / cos(60)
Velocity = 2.47 m/s
The answer is D) 2.47 m/s at 61.9 degrees
