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
tiny-mole [99]
3 years ago
7

What is the distance from axis about which a uniform, balsa-wood sphere will have the same moment of inertia as does a thin-wall

ed, hollow, lead sphere of the same mass and radius R, with the axis along a diameter, to the center of the balsa-wood sphere?
Physics
1 answer:
andrey2020 [161]3 years ago
3 0

Answer:

D_{s} ≈ 2.1 R

Explanation:

The moment of inertia of the bodies can be calculated by the equation

     I = ∫ r² dm

For bodies with symmetry this tabulated, the moment of inertia of the center of mass

Sphere               Is_{cm} = 2/5 M R²

Spherical shell   Ic_{cm} = 2/3 M R²

The parallel axes theorem allows us to calculate the moment of inertia with respect to different axes, without knowing the moment of inertia of the center of mass

    I = I_{cm} + M D²

Where M is the mass of the body and D is the distance from the center of mass to the axis of rotation

Let's start with the spherical shell, axis is along a diameter

     D = 2R

    Ic = Ic_{cm} + M D²

    Ic = 2/3 MR² + M (2R)²

    Ic = M R² (2/3 + 4)

    Ic = 14/3 M R²

The sphere

    Is =Is_{cm} + M [D_{s}²

    Is = Ic

    2/5 MR² + M D_{s}² = 14/3 MR²

    D_{s}² = R² (14/3 - 2/5)

    D_{s} = √ (R² (64/15)

    D_{s} = 2,066 R

You might be interested in
Which of the following correctly describes the importance of demonstrations to scientific investigation?
sergey [27]

Answer:

A- A demonstration shows how something works, often including models

Explanation:

A demonstration allows, through experimentation, to show how nature works and in that way can include the explanation of scientific theories that explain the set of observed facts, that is, it serves as a demonstration of the underlying scientific principles.

5 0
3 years ago
What is the mass, in kg, of a 136 pound gymnast on Earth?
Rzqust [24]

Answer:

61.6886 kg

Explanation:

6 0
2 years ago
Chapter 21, Problem 009 Two identical conducting spheres, fixed in place, attract each other with an electrostatic force of 0.12
PilotLPTM [1.2K]

Answer:

a) -1.325 μC

b) 4.17μC

Explanation:

First, you need to know that charge is conserved. So, the adition of the charges, as there is no lost in charge, should always be the same. Also, after the wire is removed, both spheres will have the same charge, trying to find equilibrium. In summary:

q_1 + q_2 = constant\\q_1_f = q_2_f |Then\\q_1_f + q_2_f = 2q_1_f = q_1_o+q_2_o\\q_1_f = q_2_f = \frac{q_1_o+q_2_o}{2}

We know both q1f and q2f must be positive, because the negative charge at the beginning was the the smaller.

The electrostatic force is equal to:

F_e = k\frac{q_1q_2}{r^2}

K is the Coulomb constant, equal to 9*10^9 Nm^2/C^2

Now, we are told that the electrostatic force after the wire is equal to 0.0443 N:

F_e_f = k \frac{q_1_fq_2_f}{r^2} = k\frac{\frac{q_1_o+q_2_o}{2}\frac{q_1_o+q_2_o}{2}}{r^2} = k\frac{(q_1_o+q_2_o)^2}{4r^2}  \\(q_1_o+q_2_o) = \sqrt{\frac{F_e_f*4r^2}{k}} = \sqrt{\frac{0.0443N *4(0.641m)^2}{9*10^9Nm^2/C^2} } = 2.844 *10^{-6}C \\ q_1_o = 2.844*10^{-6}C - q_2_o

Originally, the force is negative because it was an attraction force, therefore, its direction was opposite to the direction of the repulsive force after the wire:

F_e_o = k\frac{q_1_oq_2_o}{r^2}\\ q_1_oq_2_o = \frac{F_e_o*r^2}{k} = \frac{-0.121N(0.641m)^2}{9*10^9Nm^2/C^2} = -5.524*10^{-12}

(2.844*10^{-6}C - q_2_o)q_2_o = -5.524*10^{-12}\\0 = q_2_o^2 - 2.844*10^{-6}q_2_o - 5.524*10^{-12}

Solving the quadratic equation:

q_2_o = 4.17*10^{-6}C | -1.325 * 10^{-6}C

for this values q_1 wil be:

q_1_o =  -1.325 *10^{-6}C | 4.17*10^{-6}C

So as you can see, the negative charge will always be -1.325 μC and the positive 4.17μC

5 0
3 years ago
3. Identify three elements and three compounds. How are they<br> similar? How are they different?
Basile [38]

Answer:  A compound is a substance formed when two or more elements are chemically joined. Water, salt, and sugar are examples of compounds. When the elements are joined, the atoms lose their individual properties and have different properties from the elements they are composed of.

6 0
3 years ago
PLEASE HELP ME
vichka [17]
Go with the last one because you need potential energy for kinetic energy
8 0
2 years ago
Read 2 more answers
Other questions:
  • _ acceleration occurs when an object speeds up.<br> Answer<br> Positive
    10·2 answers
  • An object of mass m travelling at velocity u collides with an identical stationary object of mass m. After collision, both objec
    5·1 answer
  • Currents in the ocean are caused by differences in water density. Colder, denser water tends to
    9·2 answers
  • You are travelling at 60.0 mph on the Grand Central Parkway near exit 10 where it is (nearly) parallel to the Long Island Expres
    12·1 answer
  • What is the energy in joules of a photon with a frequency of 3.16e 12 s-1?
    10·2 answers
  • . An object has a position given by ~r(t) = [3.0 m − (4.00 m/s)t]ˆı + [6.0 m − (8.00 m/s2 )t 2 ]ˆ , where all quantities are in
    9·1 answer
  • Plsssssss helppppppp
    13·1 answer
  • If the horse lifts a 50 kilogram mass a vertical distance of 3 meters in 2 seconds, what is the horse’s minimum power output?
    9·1 answer
  • Describe when the chemical<br> reaction occurs in a dry-cell<br> battery
    15·1 answer
  • Suppose a child swings around her straight arm about her shoulder joint at an angular velocity of 13 rad/s. If her arm is 40. 0
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!