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
dimaraw [331]
3 years ago
9

While spinning down from 500 rpm to rest, a flywheel does 3.9 kj of work. this flywheel is in the shape of a solid uniform disk

of radius 1.2 m. what is the mass of this flywheel?
Physics
1 answer:
Ksivusya [100]3 years ago
6 0

 

The answer is 4.0 kg since the flywheel comes to rest the kinetic energy of the wheel in motion is spent doing the work. Using the formula KE = (1/2) I w².

Given the following:

I =  the moment of inertia about the axis passing through the center of the wheel; w = angular velocity ; for the solid disk as I = mr² / 2 so KE = (1/4) mr²w². Now initially, the wheel is spinning at 500 rpm so w = 500 * (2*pi / 60) rad / sec = 52.36 rad / sec.

The radius = 1.2 m and KE = 3900 J

3900 J = (1/4) m (1.2)² (52.36)²

m = 3900 J / (0.25) (1.2)² (52.36)²

m = 3.95151 ≈ 4.00 kg

You might be interested in
What’s the answer for this problem?
pickupchik [31]
The answer is always true a



4 0
3 years ago
The answer would be ?
Cerrena [4.2K]

Answer:

D. demand; increased

Explanation:

Demand is how much people want it.

4 0
3 years ago
A rough estimate of the radius of a nucleus is provided by the formula r 5 kA1/3, where k is approximately 1.3 × 10213 cm and A
Sphinxa [80]

Answer:

Density of 127 I = \rm 1.79\times 10^{14}\ g/cm^3.

Also, \rm Density\ of\ ^{127}I=3.63\times 10^{13}\times Density\ of\ the\ solid\ iodine.

Explanation:

Given, the radius of a nucleus is given as

\rm r=kA^{1/3}.

where,

  • \rm k = 1.3\times 10^{-13} cm.
  • A is the mass number of the nucleus.

The density of the nucleus is defined as the mass of the nucleus M per unit volume V.

\rm \rho = \dfrac{M}{V}=\dfrac{M}{\dfrac 43 \pi r^3}=\dfrac{M}{\dfrac 43 \pi (kA^{1/3})^3}=\dfrac{M}{\dfrac 43 \pi k^3A}.

For the nucleus 127 I,

Mass, M = \rm 2.1\times 10^{-22}\ g.

Mass number, A = 127.

Therefore, the density of the 127 I nucleus is given by

\rm \rho = \dfrac{2.1\times 10^{-22}\ g}{\dfrac 43 \times \pi \times (1.3\times 10^{-13})^3\times 127}=1.79\times 10^{14}\ g/cm^3.

On comparing with the density of the solid iodine,

\rm \dfrac{Density\ of\ ^{127}I}{Density\ of\ the\ solid\ iodine}=\dfrac{1.79\times 10^{14}\ g/cm^3}{4.93\ g/cm^3}=3.63\times 10^{13}.\\\\\Rightarrow Density\ of\ ^{127}I=3.63\times 10^{13}\times Density\ of\ the\ solid\ iodine.

7 0
3 years ago
Describe the difference between distance, position, and displacement
nata0808 [166]

Answer:

Explanation:

<em>Position is the location of the object (whether it's a person, a ball, or a particle) at a given moment in time.</em>

<em>Displacement is the difference in the object's position from one time to another.</em>

<em>Distance is the total amount the object has traveled in a certain period of time.</em>

<em />

<em>I hope this helps!</em>

<em />

5 0
2 years ago
How do tornadoes end
lilavasa [31]

Answer:

it ends when clouds above start to break apart. Some tornadoes only last seconds. Others can last much longer. They come in many shapes and sizes.

8 0
3 years ago
Read 2 more answers
Other questions:
  • A ball is released from a tower at a height of 100 meters toward the roof of another tower that is 25 meters high. The horizonta
    13·1 answer
  • please answer 1-3 and use a separate piece of paper thank you i've been trying those problems for 3 day.... ikr Sad
    5·1 answer
  • Summers are caused by
    15·2 answers
  • What is the maximum weight a boat can hold if a boat can displace 60.5ml?
    6·1 answer
  • A bullet is fired through a board 13.0 cm thick in such a way that the bullet's line of motion is perpendicular to the face of t
    6·1 answer
  • The velocity of the transverse waves produced by an earthquake is 5.08 km/s, while that of the longitudinal waves is 8.3312 km/s
    6·1 answer
  • The distance between two corresponding parts of a wave is its
    15·2 answers
  • A man drags a 71-kg crate across the floor at a constant velocity by pulling on a strap attached to the bottom of the crate. The
    15·1 answer
  • The main circuits on the system board that carry data are called the _________.
    5·1 answer
  • Dashun Mack: Attempt
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!