B. Australia and Antarctica were a single landmass in the past.
Explanation:
The most likely explanation for why the fossils of this plant are found on these two continents is that Australia and Antarctica were a single landmass in the past.
This evidence is vastly supported by the theory of plate tectonics originally, the theory of continental drift.
- Plate tectonics proposes that all land masses were once joined together as a single supercontinent called Pangaea.
- The region of Antartica and Australia were once joined as a single continental mass.
- The plant must have developed together at that time.
- When the continents moved apart, they still had the fossils.
learn more:
Continental drift brainly.com/question/5002949
#learnwithBrainly
Answer:False
Explanation:Sound waves need a mediun
Answer:
a) t = 0.75 s, b) t = 2.25 s
Explanation:
The speed of sound is constant in a material medium
v = 340 m / s
we can use the relations of uniform motion to find the time
v = x / t
t = x / v
In the exercise, the observer's distance to the wall is indicated d = 510 m, it also indicates that the shot is fired at the midpoint
x = d / 2
a) direct sound the distance from the observer to the screen is
x = 510/2 = 255 m
t = 255/340
t = 0.75 s
b) echo sound.
In this case the sound reaches the wall bounces, the distance is
x = d / 2 + d
x = 3/2 d
x = 3/2 510
x = 765 m
the time is
t = x / v
t = 765/340
t = 2.25 s
Answer:
E = h f and since f = c / λ we have E = h c / λ
Thus λ = h c / E
Also, 1 ev = 1.6E-19 C
λ = 6.63E-34 * 3.0E8 / (1.6 * 1.6E-19)
λ = 6.63 * 3.0 / (1.6 * 1.6) * E-7
λ = 7.77E-7 = 777 nanometers
(B) is correct
