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
Snezhnost [94]
3 years ago
14

The lubrication of bone joints is a subject of ongoing medical research. Two bones connected at a joint do not touch. The bones

are covered in articular cartilage, and are surrounded by lubricating synovial fluid. Rheumatoid arthritis results in overproduction of synovial fluid, swollen joints, and difficult and painful movement. Other joint disorders degrade the synovial fluid, directly increasing the friction between the bones, resulting in painful motion.
Part A



To measure the effective coefficient of friction in a bone joint, a healthy joint (and its immediate surroundings) can be removed from a fresh cadaver. The joint is inverted, and a weight is used to apply a downward force
Physics
1 answer:
maks197457 [2]3 years ago
5 0

The question is incomplete. The complete question is :

To measure the effective coefficient of friction in a bone joint, a healthy joint (and its immediate surroundings) can be removed from a fresh cadaver. The joint is inverted, and a weight is used to apply a downward force F⃗ d on the head of the femur into the hip socket. Then, a horizontal force F⃗ h is applied and increased in magnitude until the femur head rotates clockwise in the socket. The joint is mounted in such a way that F⃗ h will cause clockwise rotation, not straight-line motion to the right. The friction force will point in a direction to oppose this rotation.

Draw vectors indicating the normal force n⃗  (magnitude and direction) and the frictional force f⃗ f (direction only) acting on the femur head at point A.

Assume that the weight of the femur is negligible compared to the applied downward force.

Draw the vectors starting at the black dot. The location, orientation and relative length of the vectors will be graded

Solution :

The normal force represented by N is equal to the downward force, $F_d$ which is equal in magnitude but it is opposite in direction.

Also the frictional force acts always to oppose the motion because the bone starts moving in a clockwise direction. The frictional force that will be applied to the right direction so that the movement or the rotation at A is opposed.  

You might be interested in
In the model of the hydrogen atom due to Niels Bohr, the electron moves around the proton at a speed of 3.3 × 106 m/s in a circl
irga5000 [103]

Answer:

1.5048\times 10^{-23}\ Am^2

Explanation:

q = Charge of proton = 1.6\times 10^{-19}\ C

r = Radius of circle = 5.7\times 10^{-11}\ m

v = Velocity of proton = 3.3\times 10^6\ m/s

Magnetic moment is given by

M=\frac{1}{2}qrv\\\Rightarrow M=\frac{1}{2}1.6\times 10^{-19}\times 5.7\times 10^{-11}\times 3.3\times 10^6\\\Rightarrow M=1.5048\times 10^{-23}\ Am^2

The magnetic moment associated with this motion is 1.5048\times 10^{-23}\ Am^2

5 0
3 years ago
A tall cylinder contains 30 cm of water. Oil is carefully poured into the cylinder, where it floats on top of the water, until t
Anastaziya [24]

Answer:

The gauge pressure is  P_g  =  2058 \ P_a

Explanation:

From the question we are told that

       The height of the water contained is  h_w  =  30 \ cm  =  0.3 \ m

        The height of liquid in the cylinder is  h_t  =  40 \ cm  = 0.4 \ m

       

At the bottom of the cylinder the gauge pressure is  mathematically represented as

        P_g  =  P_w + P_o

Where  P_w is the pressure of water which is mathematically represented as

      P_w  =  \rho_w  *  g * h_w

Now  \rho_w is the density of water with a constant values of  \rho_w  = 1000 \ kg /m^3

   substituting values

      P_w  = 1000 *  9.8 *  0.3

     P_w  =  2940 \  Pa

While P_o is the pressure of oil which is mathematically represented as

          P_o  =  \rho_o *  g *  (h_t -h_w )

Where \rho _o is the density of oil with a constant value

         \rho _o  = 900 \ kg / m^3

substituting values

       P_o  =  900 *  9.8 * (0.4 - 0.3)

       P_o  =  882 \ Pa

Therefore

      P_g  =  2940 - 882

      P_g  =  2058 \ P_a

6 0
3 years ago
An object of volume 0.0882 m3 is
vfiekz [6]

The density of the fluid is 776.3 m^{-3}

<u>Explanation:</u>

Buoyant force is the upward pushing force whenever an object is trying to get immersed in fluid. So this is the force given by the fluid on the object which is trying to get immersed. The buoyant force is found to be directly proportional to the product of density of the object, volume of the object. And here the acceleration due to gravity will be acting as proportionality constant.

      Buoyant force = Density \times Volume \times Acceleration

As, buoyant force is given as 671 N and volume is 0.0882 m^{3} and acceleration is known as 9.8 m/s^{2}. Then density is

   \text { Density }=\frac{\text { Buoyant force }}{\text {Volume } \times \text {Acceleration}}

Thus,

   \text { Density }=\frac{671}{0.0882 \times 9.8}=\frac{671}{0.86436}=776.296 \mathrm{kg} / \mathrm{m}^{3}

Density is 776.3 kg m^{-3}.

7 0
3 years ago
Because energy is conserved, the “lost” energy has actually been changed into other forms. Looking at the two sleds, what effect
Shkiper50 [21]

Answer:

The answer is the kinetic energy of sled B after it crash is 6439j.

3 0
2 years ago
The average distance an electron travels between collisions is 2.0 μmμm . What acceleration must an electron have to gain 2.0×10
Ilya [14]

The solution is in the attachment

4 0
3 years ago
Read 2 more answers
Other questions:
  • Every substance has a specific value of heat required to change the temperature of 1 gram of the substance by 1 degree Celsius.
    6·1 answer
  • 1. What part of the Earth do “faults” appear?
    12·1 answer
  • What tells scientists about distant galaxies? a. How fast light travels c. The color of light that they give off b. If the are o
    5·1 answer
  • Which is an example of precipitation?
    15·1 answer
  • Un atleta que recorre 100 m en 12 s
    5·1 answer
  • What would be the force required to accelerate an object that weighs 35 N up at a rate of .60 m/s^2?
    7·1 answer
  • -
    14·1 answer
  • A 1200 N force acts on an object, resulting in an acceleration of 8.0 m/s2. What is the mass of the object?
    10·1 answer
  • A cinder block is sitting on a platform 10 m high. It has a mass of 25 Kg. What is the potential energy
    15·1 answer
  • A scientist adds different amounts of salt to 5 bottles of water. She then measures how long it takes for the water to boil. Wha
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!