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
oksian1 [2.3K]
3 years ago
9

On flat ground, a 70-kg person requires about 300 W of metabolic power to walk at a steady pace of 5.0 km/h (1.4 m/s). Using the

same metabolic power output, that person can bicycle over the same ground at 15 km/h.
A 70-kg person walks at a steady pace of 5.0 km/h on a treadmill at a 5.0% grade. (That is, the vertical distance covered is 5.0% of the horizontal distance covered.) If we assume the metabolic power required is equal to that required for walking on a flat surface plus the rate of doing work for the vertical climb, how much power is required?a. 300 W b. 315 W c. 350 WW d. 370 WW
Physics
1 answer:
Darina [25.2K]3 years ago
4 0

Answer:

C 350W

Explanation:

Given power output to walk on a flat ground to be 300W, h = 0.05x, v = 1.4m/s

m = 70kg and g =9.8m/s².

x = horizontal distance covered

Total energy used = potential energy used in climbing and the energy used in a walking the horizontal distance.

E = mgh + 300t

Where t is the time taken to cover the distance

x = vt and h = 0.05vt

So

E = mg×0.05×vt + 300t

Substituting respective values

E = 70×9.8×0.05×1.4t +300t = 348t

P = E/t = 348W ≈ 350W.

You might be interested in
The drawing shows a large cube (mass = 28.6 kg) being accelerated across a horizontal frictionless surface by a horizontal force
MrRissso [65]

Answer:

P= 454.11 N

Explanation:

Since P is the only horizontal force acting on the system, it can be defined as the product of the acceleration by the total mass of the system (both cubes).

P= (M+m)*a\\a = \frac{P}{28.6 +4.3}\\a = \frac{P}{32.9}

The friction force between both cubes (F) is defined as the normal force acting on the smaller cube multiplied by the coefficient of static friction. Since both cubes are subject to the same acceleration:

F = m * a*\mu \\F= 4.3*0.710*\frac{P}{32.9}\\F=3.053*\frac{P}{32.9}

In order for the small cube to not slide down, the friction force must equal the weight of the small cube:

3.053*\frac{P}{32.9} = 4.3 * g\\\\P = \frac{4.3*9.8*32.9}{3.053} \\P= 454.11 N

The smallest magnitude that P can have in order to keep the small cube from sliding downward is 454.11 N

8 0
3 years ago
After you enlarge a map, which one of the following scale remains correct?
9966 [12]

Answer:

None

Explanation:

An scale is the factor by which actual features on ground are enlarged or reduced for representing on a plane. There are different kinds of scales:

  • Verbal scale use of words to represent scale information on the map.  The distance or linear units are used for depicting this scale on the map.  For example: 1 inch = 1 Kilo meter.
  • Fractional scale uses the numbers or values for showing the scale instead of words. As the name says, it is represented using a fraction or ratio.  Example: 1: 10,000 or 1/10,000
  • In large scale more details are shown in a map, however, less area coverage will be shown in a single map as the scale is large and more details are given.  Example: 1:500
  • Small scale is exactly opposite to the large scale, less details are shown as magnification is not enough, however a large amount of area can be shown in a single map.  Example: 1:25,000
  • A graphic scale is a bar that has been calibrated to show map distances. On maps that have been reduced or enlarged the original ratio and written scales are incorrect, since the relationship between map distance and real world distance has been altered, graphic scale is enlarged or reduced to the same extent as the map, this makes it the right option.

I hope you find this information useful and interesting! Good luck!

6 0
3 years ago
Which forces always push in the opposite direction of motion slow stuff down.
VARVARA [1.3K]
Friction- the external force that acts on objects and causes them to slow down when no other external force acts upon them.
8 0
3 years ago
Read 2 more answers
Sino tao ang gutom?<br>A.you<br>B.mama mo!<br>C.tamod​
Fiesta28 [93]
The answer to that question is c. tamod
5 0
3 years ago
a ball is projected horizontally with a velocity of 5 m per second from the top of a building 19.6 m high how long will the ball
zepelin [54]

Answer:

1.98s

Explanation:

The time taken to hit the ground is given by

h=ut+ 1/2 at^2

but u =0

so we have

h=1/2at^2

making t the subject

t=√2h/g

√2×19.6/10

1.98s

8 0
2 years ago
Other questions:
  • When a substance changes state ____ does not change the speed of the molecules?
    11·1 answer
  • What is the following correct way to write 2,330,000 in scientific notation
    15·2 answers
  • I am getting tired quickly when I walk to school in the morning. What exercises can I do to help improve my level of fitness in
    8·2 answers
  • Which biom ha hot days, cool nights, and very few plants
    14·1 answer
  • Jane has a mass of 40 kg. She pushes on a 50 kg rock with a force of 100 N. What force does the rock exert on Jane?
    15·1 answer
  • How are the helium atoms in this model different from real helium atoms?
    14·2 answers
  • To determine<br> the force of an object what two measurements<br> are multiplied?
    10·2 answers
  • When is the acceleration of a body is positive, negative and zero?
    12·2 answers
  • Neutral hydrogen can be modeled as a positive point charge +1.6×10^−19C surrounded by a distribution of negative charge with vol
    10·1 answer
  • Which celestial objects come in direct contact with earth
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!