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
dybincka [34]
2 years ago
14

A person is sitting with one leg outstretched and stationary, so that it makes an angle of θ = 27.5° with the horizontal, as the

drawing indicates. the weight of the leg below the knee is 40.1 n, with the center of gravity located below the knee joint. the leg is being held in this position because of the force m applied by the quadriceps muscle, which is attached ℓ1 = 0.105 m below the knee joint (see the drawing). obtain the magnitude of m. (assume the angle α = 30.0° and the distance ℓ2 = 0.150 m.
Physics
1 answer:
dangina [55]2 years ago
7 0

here we will use the torque balance about the knee joint

here we can say that

\tau_g = \tau_m

here torque due to weight is given as

\tau_g = 40.1 cos\theta*(l_1 + l_2)

\tau_g = 40.1 cos27.5*(0.105 + 0.150)

\tau_g = 9.07 Nm

now torque due to applied force of muscle

\tau_m = M*sin\alpha * l_1

\tau_m = M*sin30* 0.105

now by torque balance we will have

9.07 = M*0.5*0.105

M = 173 N

so here the magnitude of m will be 173 N

You might be interested in
Despite a vigorous training schedule and careful meal planning, Anthony “hit the wall” at mile 12 of his half-marathon and he ha
Lorico [155]

Answer:

Condition of fatigue caused by depletion of glycogen

Explanation:

Let us examine how a body produces energy. There are two ways:

Fat metabolism

Fatty acids in the body help to capture adenosine triphosphate (ATP) which produces energy. On a per gram basis fatty acids yields the most ATP when oxidized completely.

Glycogen breakdown

the enzyme glycogen phosphorylase cleaves glycogen from the non reducing ends to produce monomers of glucose-1-phosphate. These monomers are used by the human body to supply energy.

When a person is exercising his/her VO₂ i.e., the oxygen consumption reaches maximum, here most of the energy comes from glycogen. While exercising most of the energy comes from glycogen breakdown.

So, when Anthony hit the wall it means that he has depleted his source of glycogen and can no longer produce glucose which provides him energy.

5 0
3 years ago
Express 34.0 cm in inches
bulgar [2K]

Hello,

1 inch = 2 centimeters

2 centimeters = 1 inch

34 / 2 = 17

Answer: 34 centimeters is 17 inches!

7 0
2 years ago
What are the characteristics of the radiation emitted by a blackbody? According to Wien's Law, how many times hotter is an objec
jasenka [17]

Answer:

a) What are the characteristics of the radiation emitted by a blackbody?

The total emitted energy per unit of time and per unit of area depends in its temperature (Stefan-Boltzmann law).

The peak of emission for the spectrum will be displaced to shorter wavelengths as the temperature increase (Wien’s displacement law).

The spectral density energy is related with the temperature and the wavelength (Planck’s law).

b) According to Wien's Law, how many times hotter is an object whose blackbody emission spectrum peaks in the blue, at a wave length of 450 nm, than a object whose spectrum peaks in the red, at 700 nm?

The object with the blackbody emission spectrum peak in the blue is 1.55 times hotter than the object with the blackbody emission spectrum peak in the red.

Explanation:

A blackbody is an ideal body that absorbs all the thermal radiation that hits its surface, thus becoming an excellent emitter, as these bodies express themselves without light radiation, and therefore they look black.

The radiation of a blackbody depends only on its temperature, thus being independent of its shape, material and internal constitution.

If it is study the behavior of the total energy emitted from a blackbody at different temperatures, it can be seen how as the temperature increases the energy will also increase, this energy emitted by the blackbody is known as spectral radiance and the result of the behavior described previously is Stefan's law:

E = \sigma T^{4}  (1)

Where \sigma is the Stefan-Boltzmann constant and T is the temperature.

The Wien’s displacement law establish how the peak of emission of the spectrum will be displace to shorter wavelengths as the temperature increase (inversely proportional):

\lambda max = \frac{2.898x10^{-3} m. K}{T}   (2)

Planck’s law relate the temperature with the spectral energy density (shape) of the spectrum:

E_{\lambda} = {{8 \pi h c}\over{{\lambda}^5}{(e^{({hc}/{\lambda \kappa T})}-1)}}}  (3)

b) According to Wien's Law, how many times hotter is an object whose blackbody emission spectrum peaks in the blue, at a wavelength of 450 nm, than a object whose spectrum peaks in the red, at 700 nm?

It is need it to known the temperature of both objects before doing the comparison. That can be done by means of the Wien’s displacement law.

Equation (2) can be rewrite in terms of T:

T = \frac{2.898x10^{-3} m. K}{\lambda max}   (4)

Case for the object with the blackbody emission spectrum peak in the blue:

Before replacing all the values in equation (4), \lambda max (450 nm) will be express in meters:

450 nm . \frac{1m}{1x10^{9} nm}  ⇒ 4.5x10^{-7}m

T = \frac{2.898x10^{-3} m. K}{4.5x10^{-7}m}

T = 6440 K

Case for the object with the blackbody emission spectrum peak in the red:

Following the same approach above:

700 nm . \frac{1m}{1x10^{9} nm}  ⇒ 7x10^{-7}m

T = \frac{2.898x10^{-3} m. K}{7x10^{-7}m}

T = 4140 K

Comparison:

\frac{6440 K}{4140 K} = 1.55

The object with the blackbody emission spectrum peak in the blue is 1.55 times hotter than the object with the blackbody emission spectrum peak in the red.

4 0
3 years ago
Three plant like organisms which cannot produce their own food are
SpyIntel [72]
I can only offer you one which is mushroom. They're fungus' and they can't produce their own food. They get their food from decaying and dead animals and absorb it through their roots.
8 0
2 years ago
A cat falls from a tree (with zero initial velocity) at time t = 0. How far does the cat fall between t = 1 2 and t = 1 s? Use G
Romashka-Z-Leto [24]

There is one mistake in the question.The Correct question is here

A cat falls from a tree (with zero initial velocity) at time t = 0. How far does the cat fall between t = 1/2 and t = 1 s? Use Galileo's formula v(t) = −9.8t m/s.

Answer:

y(1s) - y(1/2s) =  - 3.675 m  

The cat falls 3.675 m between time 1/2 s and 1 s.

Explanation:

Given data

time=1/2 sec to 1 sec

v(t)=-9.8t m/s

To find

Distance

Solution

As the acceleration as first derivative of velocity with respect to time  

So

acceleration(-g)=  dv/dt

Solve it

dv  =  a dt

dv =  -g dt

v - v₀  =  -gt

v=  dy/dt

dy  =  v dt

dy =  ( v₀ - gt ) dt

y(1s) - y(1/2s)  =  ( v₀ ) ( 1 - 1/2 ) - ( g/2 )[ ( t1)² -( t1/2s )² ]

y(1s) - y(1/2s)  = ( - 9.8/2 ) [ ( 1 )² - ( 1/2 )² ]

y1s - y1/2s  = ( - 4.9 m/s² ) ( 3/4 s² )

y(1s) - y(1/2s) =  - 3.675 m  

The cat falls 3.675 m between time 1/2 s and 1 s.

6 0
3 years ago
Other questions:
  • Two laws are described below:
    12·1 answer
  • $3.49/ gallon and other is $1.25/L which container of milk is a better deal
    7·2 answers
  • Write the equation of the line that has an undefined slope and passes through the point (4, 7). User: What is the slope of a lin
    5·2 answers
  • Which of these is an example of an elastic collision? A. The cue ball crashing into the eight balls on a pool table. B. Two cars
    9·1 answer
  • How much of the electromagnetic spectrum is visible to us? A. All of it B. None of it C. Most of it D. A small part of it
    14·2 answers
  • You and your surfing buddy are waiting to catch a wave a few hundred meters off the beach. The waves are conveniently sinusoidal
    10·2 answers
  • Rigel’s luminosity is about _____ times the sun’s luminosity.
    15·1 answer
  • Sound is a mechanical wave; therefore, it __________.
    13·2 answers
  • In Europe, gasoline efficiency is measured in km/L. If your car's gas mileage is 32.0 mi/gal , how many liters of gasoline would
    6·1 answer
  • How long does it take for a hook to reach the top of a building if the velocity is 50 m/s
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!