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3 years ago

The runners have just started a race. They started at rest and are getting faster.

Chemistry

1 answer:

Anon25 [30]3 years ago

7 0

A. Acceleration is positive and speed is increasing.

<h3>Further explanation</h3>

The motion performed by a runner is part of a uniformly accelerated motion with constant acceleration.

Equation used

$\tt \boxed{\bold{v_f=v_i+at}}$

vf = final velocity

vi = vo = initial velocity

When a runner moves from rest, his speed will increase from being at rest (vi=0) and then move with a constant acceleration(a), and as soon as he crosses the finish line his acceleration will decrease (experience a deceleration ⇒a=- ) and decrease his speed until it finally stops

Velocity and speed are different because velocity itself is a vector quantity that takes into account direction and displacement, while speed is a scalar quantity (only distance).

So the speed does not take positive or negative values because it involves direction, while acceleration takes positive and negative values (deceleration) because it takes direction.

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Calculate the density of the items below. (D = M/V)<br> 1) M = 15g V = 5.0ml *

grin007 [14]

Answer:

<h3>The answer is 3.0 g/mL</h3>

Explanation:

The density of a substance can be found by using the formula

$density = \frac{mass}{volume} \\$

From the question

mass = 15 g

volume = 5 mL

We have

$density = \frac{15}{5} \\$

We have the final answer as

Hope this helps you

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3 years ago

Q+ is an ion of element Q. What has the highest value in the ion?

Firdavs [7]

The highest value of the ion is the nucleon number. The correct option is a.

<h3>What is nucleon number?</h3>

The mass number of an element is so named because it represents the total number of protons and neutrons in the element.

The total number of protons and neutrons in an atomic nucleus is known as the mass number, also known as the atomic mass number or nucleon number. It is roughly equivalent to the atomic mass expressed in atomic mass units.

In the given ion Q+, the nucleon number has the highest value in the ion

Thus, the correct option is a.

For more details regarding nucleon number, visit:

brainly.com/question/14622763

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1 year ago

What are 3 common uses for the Uranium Element?

ipn [44]

Uranium provides nuclear fuel used generate electricity in nuclear power station,also used by the military to power nuclear submarines and in nuclear weapons.

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3 years ago

What type of effects do prostaglandins produce on smooth muscles? List two examples.

Naya [18.7K]

First, they may produce direct and relatively short-lived effects, such as stimulation of the isolated uterus or relaxation of the isolated tracheal chain preparation.

Secondly, in doses too low to produce a direct effect, they may produce a long-term potentiation of the effects of other stimulants.

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3 years ago

The reaction between carbon tetrachloride, CCl4, and water, H2O, to form carbon dioxide, CO2, and hydrogen chloride, HCl, has a

xxTIMURxx [149]

Answer:

High activation energy is the reason behind unsuccessful reaction.

Explanation:

There are two types of reaction: (1) thermodynamically controlled reaction and (2) kinetically controlled reaction.

Thermodynamically controlled reaction are associated with change in enthalpy during reaction. More negative the enthalpy change, more favored will be the reaction.

Kinetically controlled reaction are associated with activation energy of a reaction. The lower the activation energy value, the more rapid will be the reaction.

Here, reaction between $CCl_{4}$ and $H_{2}O$ is thermodynamically favored due to negative enthalpy change but the high activation energy does not allow the reaction to take place by simple mixing.

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3 years ago