Sarah is running a race and is almost to the finish line. In the last 5 seconds, her velocity changes from 2m/s to 4m/s. What is her average acceleration during the last 5 seconds of the race?

Answers

Answer 1

Answer:

[tex]\boxed {\boxed {\sf a= \frac {2}{5} \ or \ 0.4 \ m/s^2}}[/tex]

Explanation:

Acceleration is found by dividing the change in velocity by the time. The formula is:

[tex]a= \frac {v_f-v_i}{t}[/tex]

where [tex]v_f[/tex] is the final velocity, [tex]v_i[/tex] is the initial or starting velocity, and [tex]t[/tex] is the time.

Her velocity changes from 2 meters per second to 4 meters per second in the 5 seconds. Therefore:

[tex]v_f= 4 \ m/s \\v_i= 2 \ m/s \\t=5 \ s[/tex]

Substitute the values into the formula.

[tex]a= \frac { 4 \ m/s- 2 \ m/s}{5 \ s}[/tex]

Solve the numerator and subtract.

[tex]a= \frac { 2 \ m/s}{5 \ s}[/tex]

Divide.

[tex]a= \frac{2}{5} \ m/s/s= \frac{2}{5} \ m/s^2[/tex]

This can also be written as a decimal.

[tex]a=0.4 \ m/s^2[/tex]

Her average acceleration during the last 5 seconds of the race is 2/5 or 0.4 meters per square second.

Answer 2

Answer:

Solution :-

Here

Initial velocity = 2 m/s

Final velocity = 4 m/s

Time = 5 sec

v = u + at

4 = 2 + a(5)

4 - 2 = a(5)

2 = 5a

2/5 = a

Hence, acceleration is 2/5 m/s²


Related Questions

Someone help me please?

Answers

C. THERE YA GOOOOOII lol

A photon with a wavelength of 397nm is emitted from an electron in energy level 7 of a Hydrogen atom. What is the new energy level of the electron?

Answers

Answer:

New energy level is n = 2

Explanation:

ΔE = energy released by e⁻ transition n = 7 to n(final) = - h·c/λ

h = Planck's Constant = 6.63 x 10⁻³⁴ j·s

c = speed of light in vacuum = 3 x 10⁸ m/s

λ = wavelength = 397 nm = 3.97 x 10⁻⁷ m

ΔE = - (6.63 x 10⁻³⁴j·s )(3 x 10⁸ m/s)/(3.97 x 10⁻⁷ m) = - 5.01 x 10⁻¹⁹ joule

Note: this is the transitional energy 'released' by the electron moving from n = 7 energy level to n(final) energy level. As released energy, the system should be represented by an exothermic process hence, the negative value for ΔE = - h·c/λ. The equivalent amount of energy is an absorption of electromagnetic energy (EMR) to promote the electron from n(final) to n = 7 and this would be endothermic as noted with a +h·c/λ .

The Bohr Model of the electron behavior postulates electron transitions by the release of a 'discrete' amount of EMR as emission spectra defined by the expression ...

ΔE = E(final) - E(initial) => E(final) = ΔE + E(initial)

E(n) = positional (potential) energy content of electron while in energy level n and is defined by the expression E(n) = -R(H)/n²

R(H) = Rydberg Constant = 2.18 x 10⁻¹⁸ joules

n = positional energy level (in this case) = 7

E₇ = -2.18 x 10⁻¹⁸ j / (7)² = -4.45 x 10⁻²⁰ j (potential energy of n = 7 electron)

E(final) = ΔE + E₇ = (-5.01 x 10⁻¹⁹ j)  + (-4.45 x 10⁻²⁰ j) = -4.455 x 10⁻¹⁹ j

E(final) = -R(H)/n²

=> n = SqrRt[R(H)/E(final)] = SqrRt[(-2.18 x 10⁻¹⁸ j)/(-4.455 x 10⁻¹⁹)] ≅ 2

New energy level is n = 2

what evidence led to the development of the cell theory

A.scientists using microscopes

B.scientists watching bacteria divide

C.scientists seeing organelles inside cells

D.scientists reading a lot of books about cells

Answers

C is the answer To the question

What dose the T-cell attack

Answers

Answer:

killer T-cell find and destroy infected cells that have been turned into virus-making factories

can any one solve this quiz plz​

Answers

Answer:

1. It is stoichiometric.

2. O2 is the limiting reactant.

3. 9.0 g of C2H6 remain unreacted.

4. 17.6 g of CO2.

5. 85.2%.

Explanation:

Hello there!

In this case, for the given chemical reaction:

[tex]2C_2H_6+7O_2\rightarrow 4CO_2+6H_2O[/tex]

We can see that:

1. It is stoichiometric and is balanced because the reactants yields the products according to the law of conservation of mass.

2. In this part, it is possible to calculate the moles of ethane by using its molar mass:

[tex]n_{C_2H_6}=15g*\frac{1molC_2H_6}{30.08g} =0.50molC_2H_6[/tex]

And the moles of oxygen by knowing that one mole is contained in 22.4 L at STP:

[tex]n_{O_2}=\frac{1mol}{22.4L} *15.68L=0.7molO_2[/tex]

Thus, by calculating the moles of carbon dioxide product by each reactant, we can identify the limiting one:

[tex]n_{CO_2}^{by\ C_2H_6}=0.50molC_2H_6*\frac{4molCO_2}{2molC_2H_6} =1.0molCO_2\\\\n_{CO_2}^{by\ O_2}=0.70molO_2*\frac{4molCO_2}{7molO_2} =0.4molCO_2\\[/tex]

Thus, since oxygen yields the fewest moles of CO2 product, we infer it is the limiting reactant.

3. In this part, we calculate the mass of C2H6 that actually react first:

[tex]m_{C_2H_6}^{reacted}=0.4molCO_2*\frac{2molC_2H_6}{4molCO_2}*\frac{30.08gC_2H_6}{1molC_2H_6} =6.0gC_2H_6[/tex]

Thus, the leftover of ethane (C2H6) as the excess reactant is:

[tex]m_{C_2H_6 }^{leftover}=15g-6.0g=9.0g6.0C_2H_6[/tex]

4. Since 0.4 moles of carbon dioxide were produced, we use its molar mass to calculate the mass as its theoretical yield:

[tex]m_{O_2}^{theoretical}=0.4molCO_2*\frac{44gCO_2}{1molCO_2}=17.6gCO_2[/tex]

5. Finally, the percent yield is gotten by dividing the actual yield by the theoretical one:

[tex]Y=\frac{15g}{17.6}*100\%\\\\Y=85.2\%[/tex]

Best regards!

How many moles are represented by 86.5 g of Ca(OH)2?
*please help fast*

Answers

Answer:

30 2 the second power

Explanation:

Calcium hydroxide, commonly known as hydrated lime or slaked lime, is a soft white powder that is used as a primary ingredient in the chemical industry.

What is Calcium Hydroxide?

Its chemical formula is Ca(OH)2. When calcium oxide and water are combined, it produces.

There are two hydroxide ions (OH) in the molecule for every calcium ion (Ca2+). The substance is ionic, and both electrolytic and aqueous dissociations result in calcium and hydroxide ions.

When water is added to dry portland cement to create concrete, this reaction takes place, and the mixture warms up and releases heat. An alternative method of manufacturing entails an aqueous double displacement reaction between sodium hydroxide and calcium chloride.

Therefore, Calcium hydroxide, commonly known as hydrated lime or slaked lime, is a soft white powder that is used as a primary ingredient in the chemical industry.

To learn more about Calcium hydroxide, refer to the link:

https://brainly.com/question/31566398

#SPJ2

what is the molarity of a solution in which 10.0 g of AgNO3 is dissolved in 5 L of a solution

Answers

Answer:

no of moles = given mass/molar mass

no of moles = 10/169.87 =0.058moles

molarity = number of moles of solute/volume of solution in litre

molarity = 0.058/5

molarity = 0.0116

During the formation of the sun, gravity pulled matter closer and closer
together until what event occurred?

A. Radioactive decay began.

B. Nuclear fusion reactions began.

C.Neutrons and protons formed.

D. A nebula exploded.

Answers

Answer:

c

Explanation:

cuz


Tides are the result of forces exerted on Earth's oceans, mostly by which celestial body?
The Sun
Jupiter
The Moon
Venus

Answers

The answr is the moon

Answer:

Explanation:

The moon

Copper extraction symbol equation

Answers

Answer:

Fe(s) + Cu2+(aq) ===> Fe2+(aq) + Cu(s)

Answer:

2CuFeS2+2SiO2+4O2→Cu2S+2FeSiO3+3SO2(1)

Explanation:

2CuFeS2+2SiO2+4O2→Cu2S+2FeSiO3+3SO2(1)

What does a base release when it is placed in water?
Select one:
a.Chloride ion (Cl-)
b.Hydronium ion (H3O+)
c.Calcium ion (Ca2+)
d.Hydroxide ion (OH-)

Answers

Answer:

D - Hydroxide Ion (OH-)

Explanation:

A base provides either hydroxide ions (OH–) or other negatively charged ions that combine with hydrogen ions, reducing their concentration in the solution and thereby raising the pH. In cases where the base releases hydroxide ions, these ions bind to free hydrogen ions, generating new water molecules.

help please and show work!

Answers

Answer:

Mg + 2HCl → MgCl2 + H2

Explanation:

Mg (s) + 2HCl (aq) → MgCl2 (aq) + H2

what particle has a mass & charge?

a. alpha particle
b. beta particle
c. gamma ray

Answers

Answer:

A. Alpha Particle

Explanation:

I think i could be wrong

What force pulls the water down hill in a watershed, preventing it from going
OVER the drainage divide? *

Answers

Answer:

gravity

Explanation:

force downward due to gravity

Answer:

Gravity is the answer.

Which One Is the Wrong One?

Answers

Answer:

I would say the second one it's the wrong

What is the volume of a gas if the gas has a volume of 100.0 L at 135 C. What is the volume of the gas if its temperature decreases to 72.0 C

Answers

Answer: The volume of gas is 84.6 L at [tex]72.6^0C[/tex]

Explanation:

To calculate the final volume of the system, we use the equation given by Charles' Law. This law states that volume of the gas is directly proportional to the temperature of the gas at constant pressure.

Mathematically,

[tex]\frac{V_1}{T_1}=\frac{V_2}{T_2}[/tex]

where,

[tex]V_1\text{ and }T_1[/tex] are the initial volume and temperature of the gas.

[tex]V_2\text{ and }T_2[/tex] are the final volume and temperature of the gas.

We are given:

[tex]V_1=100.0L\\T_1=135^oC=(135+273)K=408K\\V_2=?\\T_2=72.0^0C=(72.0+273)K=345K[/tex]

Putting values in above equation, we get:

[tex]\frac{100.0L}{408K}=\frac{V_2}{345K}\\\\V_2=84.6L[/tex]

Thus the volume of gas is 84.6 L at [tex]72.6^0C[/tex]

The level of mercury in a barometer falls as the air pressure falls.

True
False

Real answers only or you will be reported and banned from brainly

Answers

Answer:True

Explanation:

______________________________ is the attraction amongst molecules that are dissimilar.

A.) Transpiration
B.) Cohesion
C.) Adhesion
D.) Polarity

Answers

Answer:

ily

Explanation:

if people are blind can they dream

Answers

Answer:

yeah they dream in weird shapes mostly I think. unless they weren't born blind then they dream normally I think

Answer:

Kind of, our dreams refer to what we see, but blind people can't see, they might have dreams what the world might look like

How does energy from the Sun drive the cycling of matter?

Answers

Answer:

solar energy drives the cycle by evaporating water from the oceans, lakes, rivers, and soil. As liquid water evaporates or transpires, it forms water vapor and clouds, where water droplets eventually gain enough mass to fall back to Earth as precipitation.

Silicon can be made by heating a mixture of sand (silicon dioxide) with magnesium
powder.
The equation for this reaction is shown below.
SiO2 (s)+ 2Mg (s) → 2MgO (s) + Si (s)
Calculate the mass of silicon dioxide needed to make 1 g of silicon.
Relative atomic masses: O = 16; Si = 28
Mass = ?

Answers

Answer:

[tex] \frac{60}{28} = \frac{15}{7} [/tex]

Which step(s) of the greenhouse effect are being most affected by the increases in greenhouse gases, leading to an increase in heat? 1. Solar radiation enters the Earth system and is reflected and absorbed. 2. Absorbed energy is released into the atmosphere as heat. 3. Heat is absorbed by the atmosphere. 4. The atmosphere re-releases heat, warming Earth's surface and lower atmosphere. 1 and 2 2, 3 and 4 1, 2, and 3 3 and 4

Answers

Answer:

Answers of the greenhouse effect 1 ,3 and 4

Color blindness is a sex-linked, _______ trait.
-recesive
-dominat
-multiple allele
-multiple dominance

Answers

Answer:

recessive trait

Answer:

recessive

Explanation:

Color blindness is a sex-linked, recessive trait.

hope this helps and is right :)

C time
2. An instrument used to measure force is
B. spring balance
A ruler
D) wind vane
C. thermometer
of ford​

Answers

Answer:

B. Spring balance - a device used for measuring the weight or force of gravity acting on an object.

Explanation:

A Force is any interaction that changes the motion or position of an obkpjectbthatbit is interacting with. Whenever there is an interaction between two objects, there is a force exerted by each of the objects on one themselves.

Forces are generally divided into contact forces and non-contact over field forces.

In contact forces, the two objects physically in contact with each other. Examples of contact forces are push or pull forces, frictional forces, tensional forces, spring forces, etc.

Non-contact forces are forces in which the two objects interacting do no need to be physically in contact with one another. Examples include, gravitational forces, magnetic forces, electrical forces, etc.

Instruments used in measuring forces are known as force gauges.

From the instruments listed above:

A. A ruler is an instrument used in measuring length

B. Spring balance is a device used for measuring the weight or force of gravity acting on an object.

C. A thermometer is an instrument used in measuring temperature

D. A windbvane is an instrument used in measuring wind direction.

which two things cause the orbits of the planets to be the nearby circular
Inertia
gravity
electricity
magnetism

Answers

Answer:Gravity and inertia

Which solute, an electrolyte or a nonelectrolyte, has the greater effect on the boiling point when a given amount of each
solute is dissolved in the same mass of water?
O The nonelectrolyte does because it disperses into molecules.
O The electrolyte does because it disperses into molecules.
O The nonelectrolyte does because it dissociates into ions.
O The electrolyte does because it dissociates into ions.

Answers

The solute wether electrolyte or a nonelectrolyte, has the greater effect on the boiling point when a given amount of each solute is dissolved in the same mass of water The nonelectrolyte does because it dissociates into ions.

What is a solute?

Solute refers to substances or liquid which can readily dissolve in a solvent. It's concentration is lower to that of solvent.

Therefore, The solute wether electrolyte or a nonelectrolyte, has the greater effect on the boiling point when a given amount of each solute is dissolved in the same mass of water The nonelectrolyte does because it dissociates into ions

Learn more about solute below.

https://brainly.com/question/16083884

#SPJ2

Answer:

D: The electrolyte does because it dissociates into ions.

Explanation:

The scientist who wrote the universal law of gravitation was

Answers

The scientist who wrote the universal law of gravitation was Sir Isaac Newton.

The scientist that wrote the universal law of gravitation was Isaac Newton.

What is the universal law of gravitation?

The universal law of gravitation states that every object in this universe attracts every other object around it with a force, whose magnitude is directly proportional to the product of their masses and indirectly proportional to the square of the distance between them.

The universal law of gravitation was first published by the scientist Issac Newton in the year 1687.

Learn more about force here:

https://brainly.com/question/30236242

#SPJ6

Contains a nonmetal and metal

A) base

B) acid

C) covalent bond

D) salt

Answers

Salt - Na Cl
Sodium(metal) and chloride(nonmetal)

Acid rain due to air pollution when water reacts with sulfur dioxide, nitric oxide, and carbon dioxide, causes

Answers

Answer:

Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.

Explanation:

How can a chemical reaction be sped up? Select from the drop-down menu to correctly complete the statement. Add a Choose... that is unaffected by a reaction. the choices are, A: catalyst B: coefficient C: product

Answers

Answer:

A: catalyst

Explanation:

In Chemistry, the rate of reaction of chemical elements (reactants) can be sped to produce a chemical compound or elements (products), through the addition of a catalyst that is unaffected by the reaction.

This ultimately implies that, to speed up a chemical reaction, add a catalyst that is unaffected by a reaction.

For example, an enzyme refers to a biological catalyst that is typically used to speed up (accelerate) the rate of a chemical reaction by lowering the activation energy of its reactants.

An enzyme can be defined as a biological catalyst that typically lowers the activation energy of a biological reaction. When the activation energy of a reaction is low, the rate of the reaction would be faster. Therefore, an enzyme speeds or catalyzes the rate of a reaction by lowering its activation energy.

Generally, an increase in temperature increases or speeds up the rate of a reaction while low temperature limits or reduces the rate of a reaction. The optimal temperature for enzymes in the human body is around 37 degrees celsius.

Other Questions
Which of the following is a property of elements?OElements have at least two different types of atoms.Elements have their own individual characteristic properties.Elements are can be separated from one another.Elements have the ability to change into a different element. it is b not a not c and it not d How does wind affect the amount of rain? Please help ASAP!!!!! Help me!!!!!In animation, a figure refers to...A. Any object B. Only people C. Only animals D. The backround How does inheritance help future generations accumulate wealth ? If you are trying to move your audience to do something, you should choose which organizational style?a. topicalb. cause-effectc. motivated sequenced. problem-solutionPlease select the best answer from the choices provided What is the speed of a 1.57 N bullet traveling with a total momentum equal to 131 Kg.m/s? PLEASE HELP!!!!!!!!!_______ Where did African Americans receive the best treatment? 1. Le blank a mi chofer que me condujese hasta aquel barrio what is the circumfrence of a circle with a radius of 4 inches. Use 3.14 for pi. The half-life of argon-39 is 269 years. It decays into krypton-39. After 1,076 years, what fraction of the original amount of argon-39 in a sample will still be argon 1/161/4 1/21/8 Riley earned $5 for 1/2 of an hour babysitting. What is her hourly rate?Simplify your answer and write it as a proper fraction, mixed number, or whole number. Gull Corp. is considering selling its old popcorn machine and replacing it with a newer one. The old machine has a book value of $5,000, and its remaining useful life is five years. Annual costs are $4,000. A high school is willing to buy it for $2,000. New equipment would cost $18,000 with annual operating costs of $1,500. The new machine has an estimated useful life of five years.Should the machine be replaced?Proposal to Replace Equipment Annual Variable Costs - Present Equipment $ Annual Variable Costs - New Equipment Annual Differential Decrease in Cost $ Number of Years Applicable Total Differential Decrease in Cost $ Proceeds from Sales of Present Equipment $Cost of New Equipment Annual Net Differential Increase in Cost - New Equipment $ Help with question 4 and 5 plllllllllllllllllllllllllllz asap simplify (4m)^2 What is the wavelength associated with 0.113kg ball traveling with velocity of 43 m/s? Why should organisms that produce more offspring have a more likely chance of survival? Please help I forgot how to do this