26.5, I’m not sure if it’s right but 1060/40 gets that
The dinosaurs first appeared in the Mesozoic and the first mass extinction occurred during the Paleozoic. Moreover, humans first appeared in the Cenozoic.
<h3>The geological eras and biological events</h3>
The dinosaurs emerged during the Triassic Period of the Mesozoic Era, approximately 220-225 million years ago.
The first mass extinction occurred in the Ordovician Period (the second period of the Paleozoic Era).
The Cenozoic is the current geological Era that encompasses the last 60 million years.
Learn more about geological eras here:
brainly.com/question/1288853
Lets assume that s is the speed of the slower train and f is the speed of the faster train.
s = f - 16
f = 150 / t
s = 170 / ( t+2 )
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170 / ( t+2 ) = 150 / t - 16 / t * ( t + 2 )
170 t = 150 * ( t + 2 ) - 16 t * ( t + 2 )
170 t = 150 t + 300 - 16 t² - 32 t
16 f² + 52 t - 300 = 0 / : 4 ( We will divide both sides of the equation by 4 )
4 t² + 13 t - 75 = 0
t 1/2 = ( -13 + √(169 + 1200 ) )/ 8
t = ( - 13 + 37 ) / 8 = 24 / 8 = 3
t = 3 h
s = 170 : ( 3 + 2 ) = 170 : 5 = 34 mph
Answer: The speed of the slower train is 34 mph.
<h3>2
Answers:</h3>
a) Velocity is a vector quantity
e) Velocity is a speed with direction
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Explanation:
If we know the velocity of an object, then we know how fast it's going (speed) and where it's going (direction). It is a vector because the direction of the vector determines the direction, and the length of the vector (aka magnitude) determines the speed. So in a sense we've built in two facts of data into one visual.
An example of velocity: 10 miles per hour north. Here we have the speed of 10 mph and the direction north.
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Extra info:
- Choice B contradicts choice A, so we can cross choice B off the list.
- Choice C is false because speed is a scalar, or single quantity, and not a vector. As mentioned earlier, speed is a part of velocity, but they aren't the same exact thing.
- Choice D is false because the velocity does not account for net force. We don't have any force information built into the velocity.
Acceleration = 14/4 = ....
