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
Shalnov [3]
3 years ago
8

A world class runner can run long distances at a pace of 15 km/hour. That runner expends 800 kilocalories of energy per hour. a)

Find the power (in Watts [W]) the runner is exerting while running. b) Find the total energy (in Joules [J]) exerted by the runner in a 15 km run. c) How many Milky Way (Original Single 52.2g) chocolate bars does the runner need to buy to supply the amount of energy to complete a half-marathon (13.1 miles)? (Cite your source for the number of calories in a Milky Way bar)
Engineering
1 answer:
maks197457 [2]3 years ago
7 0

Answer: a) 1.05kW b) 3.78MJ c) 5.3 bars

Explanation :

A)

Conversions give 900 kcal as 900000 x 4.2 J/cal {4.2 J/cal is the standard factor}

= 3780kJ

And 1 hour = 3600s

Therefore, Power in watts = 3780/3600 = 1.05kW = 1050W

B)

At 15km/hour a 15km run takes 1 hour.

1 hour is 3600s and the runner burns 1050 joule per second.

Energy used in 1 hour = 3600 x 1050 J/s

= 3780000 J or 3.78MJ

C)

1 mile = 1.61km so 13.1 mile is 13.1 x 1.61 = 21.1km

15km needs 3.78 MJ of energy therefore 21.1km needs 3.78 x 21.1/15 = 5.32MJ =5320 kJ

Finally,

1 Milky Way = 240000 calories = 4.2 x 240000 J = 1008000J or 1008kJ

This means that the runner needs 5320/1008 = 5.3 bars

You might be interested in
"Write a statement that outputs variable numItems. End with a newline. Program will be tested with different input values."
kirill [66]

Answer:

The solution code is written in Java.

System.out.println(numItems);

Explanation:

Java <em>println() </em>method can be used to display any string on the console terminal. We can use <em>println()</em> method to output the value held by variable <em>numItems.</em> The <em>numItems </em>is passed as the input parameter to <em>println()</em> and this will output the value of <em>numItems</em> to console terminal and at the same time the output with be ended with a newline automatically.  

6 0
3 years ago
Consider a fan located in a 3 ft by 3 ft square duct. Velocities at various points at the outlet are measured, and the average f
natulia [17]

Answer:

minimum electric power consumption of the fan motor is 0.1437 Btu/s

Explanation:

given data

area = 3 ft by 3 ft

air density = 0.075 lbm/ft³

to find out

minimum electric power consumption of the fan motor

solution

we know that energy balance equation that is express as

E in - E out  = \frac{dE \ system}{dt}    ......................1

and at steady state  \frac{dE \ system}{dt} = 0

so we can say from equation 1

E in = E out

so

minimum power required is

E in = W = m \frac{V^2}{2} = \rho A V \frac{V^2}{2}  

put here value

E in =  \rho A V \frac{V^2}{2}  

E in =  0.075 *3*3* 22 \frac{22^2}{2}  

E in = 0.1437 Btu/s

minimum electric power consumption of the fan motor is 0.1437 Btu/s

5 0
3 years ago
The moisture content in air (humidity) is measured by weight and expressed in pounds or ____________________.
VikaD [51]

Moisture content is measured in terms of pounds of water per pound of air (lb water/lb air) or grains of water per pound of air (gr. of water/lb air).

Hope this helps❤

3 0
2 years ago
Basil is installing a system in Toronto, Ontario where they are wide temperature variations. What is the TD of the system he’s i
marysya [2.9K]
In places with cold winters, space heating systems have a fundamental role in buildings. Without them, indoor temperatures would quickly become unsuitable for human occupancy. The local weather is one of the most important factors when designing a heating system; if two identical buildings are developed in Miami FL and New York City, the heating load will be much higher for the NYC property.

4 0
3 years ago
Electric heater wires are installed in a solid wall having a thickness of 8 cm and k=2.5 W/m.°C. The right face is exposed to an
Svet_ta [14]

Answer:

2.46 * 10⁵ W/m³

Explanation:

See attached pictures for detailed explanation.

6 0
3 years ago
Read 2 more answers
Other questions:
  • Two players find themselves in a legal battle over a patent. The patent is worth 20 for each player, so the winner would receive
    14·1 answer
  • A mass of 0.3 kg is suspended from a spring of stiffness 0.4 N/mm. The damping is 3.286335345 kg/s. What is the undamped natural
    5·1 answer
  • Technician A says that latent heat is hidden heat and cannot be measured on a thermometer. Technician B says that latent heat is
    12·1 answer
  • The products of combustion from a burner are routed to an industrial application through a thin-walled metallic duct of diameter
    11·1 answer
  • Two kilograms of air within a piston–cylinder assembly executes a Carnot power cycle with maximum and minimum temperatures of 80
    5·2 answers
  • HELP PLEASE!!!!
    12·1 answer
  • I NEED HELP ASAP WILL AWARD BRAINLIEST
    8·2 answers
  • CAN SOMEONE GIVE ME AND ANSWER AND EXPLANTION FOR ALL THESE QUESTIONS PLEASE, I AM STRUGGLING
    15·1 answer
  • Cody’s car accelerates from 0m/s to 45 m/s northward in 15 seconds. What is the acceleration of the car
    14·1 answer
  • Since you became discouraged not being able to find a job in the San Diego area, you enlarged the area in which you looked for a
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!