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Mariana [72]
3 years ago
8

Humans first appeared during the _____.

Physics
2 answers:
Alinara [238K]3 years ago
8 0
<span>Humans first appeared during the Quaternary period. <span>The Quaternary or Neozoic period develops in the Cenozoic era, which extends from 2,588 million years ago to the present. The Quaternary is divided into two periods. The Pleistocene, the first and longest period of the period, was characterized by the cycles of glaciations and the appearance of the first humans (homos habilis); this period extended from 2,588 million years to 10,000 years BC The Holocene, the second epoch of the period, was characterized by the end of the glaciation and the emergence of human civilization; this period extends from 10,000 years BC to the present.</span></span>
sergeinik [125]3 years ago
6 0

your answer is Quaternary period

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A ball is kicked from level ground at an angle 60° with initial velocity 10 m/s. The distance the ball travels, in meters, is:
RUDIKE [14]

Answer:

<em>the ball travels a distance of 8.84 m</em>

Explanation:

Range: Range is defined as the horizontal distance from the point of projection to the point where the projectile hits the projection plane again.

R = (U²sin2∅)/g.............................. Equation 1

Where R = range, U = initial velocity, ∅ = angle of projection, g = acceleration due to gravity.

<em>Given: U = 10 m/s, ∅ = 60°</em>

<em>Constant: g = 9.8 m/s²</em>

Substituting these values into equation 1

R = [10²×sin(2×60)]/9.8

R = (100sin120)/9.8

R = 100×0.8660/9.8

R = 86.60/9.8

R = 8.84 m

<em>Therefore the ball travels a distance of 8.84 m</em>

4 0
3 years ago
A thermometer containing 0.10 g of mercury is cooled from 15 degrees celsius to 8.5 degrees celcius. How much energy left the me
loris [4]

To solve this exercise we will use the concept related to heat loss which is mathematically given as

Q = mC_p \Delta T

Where,

m = mass

C_p= Specific Heat

\Delta T = Change in temperature

Replacing with our values we have that

m = 0.1g

C_p = 139J/Kg\cdot K \rightarrow Specific heat of mercury

\Delta T = 8.5\°C-15\°C = -6.5\°C \Rightarrow -6.5K

Replacing

Q = (0.1*10^3)(138)(-6.5)\\Q = -0.09J

Therefore the heat lost by mercury is 0.09J

5 0
3 years ago
This equation shows the reaction that occurs when calcium carbonate
yarga [219]

Answer:

a. endothermic

Explanation:

The reaction shown is an endothermic reaction. In such reaction, they require an input of energy.

  • Endothermic changes involves absorption of heat from the surrounding.
  • The surrounding becomes colder at the end of the reaction.
  • When heat is on the reactant side, it suggests a reaction that requires a considerable input of energy.
3 0
3 years ago
Read 2 more answers
Which statement best summarizes Gregor Mendel’s contribution to science?
Rama09 [41]
Hey there!

<span>Which statement best summarizes Gregor Mendel’s contribution to science?

Mendel is considered the "father of genetics". He did NOT increse the number of peas </span>
<span>produced by a single plant using cross-breeding techniques, discover grean peas and yellow peas, or invent the green pea by cross-breeding thousands of pea plants.

This means your answer is option D.

Hope this helps
Have a great day (:
</span>
8 0
3 years ago
Read 2 more answers
What law states that, in any process, energy is neither created nor destroyed?
kupik [55]
The law<span> of conservation of </span><span>energy.</span>
8 0
3 years ago
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