1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
AURORKA [14]
3 years ago
12

In an extreme marathon, participants run a total of 100km; world-class athletes maintain a pace of 15 km/h. how many 230 Calorie

energy bars would be required to fuel such a run for a 68 kg athlete?

Physics
2 answers:
MAVERICK [17]3 years ago
7 0

speed of the participants is given as

v = 15 km/h

v = 15 \times \frac{1000 m}{3600s} = 4.2 m/s

now the kinetic energy of the participant is given as

KE = \frac{1}{2}mv^2

KE = \frac{1}{2}68\times 4.2^2

KE = 590.3 J

As we know that

1 calorie = 4.2 J

KE = 590.3\times \frac{1 cal}{4.2J} = 141.1 Cal

so here 230 Calorie is provided by 1 bar

bar required is

N = \frac{141.1}{230} = 0.61 bars

azamat3 years ago
7 0

1 energy bar would be required to fuel such a run for a 68 kg athlete

\texttt{ }

<h3>Further explanation</h3>

<em>Let's recall </em><em>Kinetic Energy</em><em> Formula as follows:</em>

\large {\boxed{Ek = \frac{1}{2}mv^2} }

Ek = Kinetic Energy ( Joule )

m = mass of the object ( kg )

v = speed of the object ( m/s )

Let us now tackle the problem !

\texttt{ }

<u>Given:</u>

speed of participant = v = 15 km/h = 4¹/₆ m/s

mass of participant = m = 68 kg

<u>Asked:</u>

kinetic energy = Ek = ?

<u>Solution:</u>

<em>Firstly , we will calculate total kinetic energy of the participant:</em>

Ek = \frac{1}{2}m(v')^2

Ek = \frac{1}{2} \times 68 \times (4\frac{1}{6})^2

Ek = 590 \frac{5}{18} \texttt{ J}

Ek \approx 141 \texttt{ Calories}

\texttt{ }

<em>Next , we could find number of </em><em>230 Calorie Energy Bars</em><em> as follows:</em>

N = Ek / 230

N = 141 / 230

N \approx 0.61

<h3>Conclusion:</h3>

1 energy bar would be required to fuel such a run for a 68 kg athlete

\texttt{ }

<h3>Learn more</h3>
  • Impacts of Gravity : brainly.com/question/5330244
  • Effect of Earth’s Gravity on Objects : brainly.com/question/8844454
  • The Acceleration Due To Gravity : brainly.com/question/4189441
  • Newton's Law of Motion: brainly.com/question/10431582
  • Example of Newton's Law: brainly.com/question/498822

\texttt{ }

<h3>Answer details</h3>

Grade: High School

Subject: Physics

Chapter: Dynamics

You might be interested in
The curvature of the helix r​(t)equals(a cosine t )iplus(a sine t )jplusbt k​ (a,bgreater than or equals​0) is kappaequalsStartF
4vir4ik [10]

Answer:

\kappa = \frac{1}{2 b}

Explanation:

The equation for kappa ( κ) is

\kappa = \frac{a}{a^2 + b^2}

we can find the maximum of kappa for a given value of b using derivation.

As b is fixed, we can use kappa as a function of a

\kappa (a) = \frac{a}{a^2 + b^2}

Now, the conditions to find a maximum at a_0 are:

\frac{d \kappa(a)}{da} \left | _{a=a_0} = 0

\frac{d^2\kappa(a)}{da^2}  \left | _{a=a_0} < 0

Taking the first derivative:

\frac{d}{da} \kappa = \frac{d}{da}  (\frac{a}{a^2 + b^2})

\frac{d}{da} \kappa = \frac{1}{a^2 + b^2} \frac{d}{da}(a)+ a * \frac{d}{da}  (\frac{1}{a^2 + b^2} )

\frac{d}{da} \kappa = \frac{1}{a^2 + b^2} * 1 + a * (-1)  (\frac{1}{(a^2 + b^2)^2} ) \frac{d}{da}  (a^2+b^2)

\frac{d}{da} \kappa = \frac{1}{a^2 + b^2} * 1 - a  (\frac{1}{(a^2 + b^2)^2} ) (2* a)

\frac{d}{da} \kappa = \frac{1}{a^2 + b^2} * 1 -  2 a^2  (\frac{1}{(a^2 + b^2)^2} )

\frac{d}{da} \kappa = \frac{a^2+b^2}{(a^2 + b^2)^2}  -  2 a^2  (\frac{1}{(a^2 + b^2)^2} )

\frac{d}{da} \kappa = \frac{1}{(a^2 + b^2)^2} (a^2+b^2 -  2 a^2)

\frac{d}{da} \kappa = \frac{b^2 -  a^2}{(a^2 + b^2)^2}

This clearly will be zero when

a^2 = b^2

as both are greater (or equal) than zero, this implies

a=b

The second derivative is

\frac{d^2}{da^2} \kappa = \frac{d}{da} (\frac{b^2 -  a^2}{(a^2 + b^2)^2} )

\frac{d^2}{da^2} \kappa = \frac{1}{(a^2 + b^2)^2} \frac{d}{da} ( b^2 -  a^2 ) + (b^2 -  a^2) \frac{d}{da} ( \frac{1}{(a^2 + b^2)^2}  )

\frac{d^2}{da^2} \kappa = \frac{1}{(a^2 + b^2)^2} ( -2  a ) + (b^2 -  a^2) (-2) ( \frac{1}{(a^2 + b^2)^3}  ) (2a)

\frac{d^2}{da^2} \kappa = \frac{-2  a}{(a^2 + b^2)^2} + (b^2 -  a^2) (-2) ( \frac{1}{(a^2 + b^2)^3}  ) (2a)

We dcan skip solving the equation noting that, if a=b, then

b^2 -  a^2 = 0

at this point, this give us only the first term

\frac{d^2}{da^2} \kappa = \frac{- 2  a}{(a^2 + a^2)^2}

if a is greater than zero, this means that the second derivative is negative, and the point is a minimum

the value of kappa is

\kappa = \frac{b}{b^2 + b^2}

\kappa = \frac{b}{2* b^2}

\kappa = \frac{1}{2 b}

3 0
3 years ago
A car covers 400 km in an hour towards west .calculate the velocity​
crimeas [40]

Answer:

-400km/hr

Explanation:

Velocity=displacement/time

=400/1

=400Km/hr

=-400km/hr (because west direction)

7 0
2 years ago
A............... pulley helps us by changing the direction of the applied effort​
DerKrebs [107]

Explanation:

Malai thaxai. na

ffndgufijvdyfbffnfcjoigkf

8 0
2 years ago
Read 2 more answers
What is kirchoff s law???
kolbaska11 [484]
There are two laws named for Kirchhoff.  The both concern electrical circuits.
Here they are in my own words:

1).  The sum of the voltage drops around any closed loop in a circuit is zero.

2).  The sum of the currents at any single point in a circuit is zero.
8 0
3 years ago
Read 2 more answers
Which term means the distance between two bridge supports?
Ad libitum [116K]

The best answer is b - span.

A span is the distance between two bridge supports The supports may be towers, columns, or even the wall of a canyon.

There are many kinds of bridges  but they all fall into three types namely beam, arch and suspension. The major difference between these three kinds of bridges is the distance that each can cross in  a single span.

For example, a modern beam bridge is likely to span a distance of 200 feet, a modern arch can span 800 or 1000feet,  and a modern suspension bridge can span up to 7000ft.


5 0
2 years ago
Other questions:
  • Which describes newton’s law of universal gravitation?
    6·1 answer
  • A plane mirror and a concave mirror (f = 8.20 cm) are facing each other and are separated by a distance of 25.0 cm. An object is
    11·2 answers
  • A stock person at the local grocery store has a job consisting of the following five segments:
    12·1 answer
  • Illustrated here are three different<br> of carbon. They vary by the number of
    13·1 answer
  • 7. The uranium nucleus contains a charge 92 times that of the proton. If a proton is shot at the nucleus, how large a repulsive
    12·1 answer
  • A calculator has a resistance of 22 Ω. What is the power rating for this calculator when connected to a 1.5 V battery?
    13·1 answer
  • Occurs when the moon moves between the Earth and Sun and blocks the light
    15·2 answers
  • How many feet does a No. 2 pencil last?
    11·1 answer
  • When discussing distances between objects in the solar system, which term do you use?
    14·2 answers
  • A circuit in a radio receiver requires a current of at least 1.0 microamp in order to detect a signal. How many electrons pass t
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!