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
sergeinik [125]
3 years ago
5

A string is wound around a uniform disc of radius 0.68 m and mass 3.7 kg. The disc is released from rest with the string vertica

l and its top end tied to a fixed support. calculate the speed of the center of mass when, after starting from rest, the center of mass has fallen 1.2 m. The acceleration of gravity is 9.8 m/s 2 . Answer in units of m/s.
Physics
1 answer:
Zolol [24]3 years ago
8 0

Answer:

3.962

Explanation:

mass = 1.2

gravity g = 9.81

velocity = ?

mgh = 1/2mv² + 1/2(1/2)mv²

= 9.81 x 1.2  = 3/4v²

11.772 x 4 = 3/4v²

47.088 = 3v²

divide through both sides by 3

15.696 = v²

take the square root of both sides

√15.696 = √v²

= 3.6962 = v

the speed is therefore 3.692

You might be interested in
Is it possible for a system to have negative potentialenergy?
sineoko [7]

Answer:

Yes, since the choice of the zero o potential energy is arbitrary.

Explanation:

The kinetic energy is due to the motion of the object. The expression for the kinetic energy is as follows;

KE=\frac{1}{2}mv^{2}

Here, m is the mass of the object and v is the velocity of the object.

The kinetic energy can not be negative as the velocity is squared. It can be zero and positive.

Potential energy: It is the energy is due to the position of the object.

The expression for the potential energy is as follows;

PE= mgh

Here, g is the acceleration due to gravity and height.

Height can be taken from the reference point, zero which can be taken below zero and above zero. Zero is taken as origin. Below zero, the height is taken as negative and above zero, the height is taken as positive.

The potential energy can be zero, positive and negative.

The total energy is the sum of kinetic energy and potential energy.

E= KE + PE

Here, KE is the kinetic energy and PE is the potential energy.

Therefore, the option (B) is correct.

5 0
2 years ago
An electric lamp creates light by forcing electrons through the filament of its light bulb. The kinetic energy of the moving ele
ollegr [7]

electric potential energy..electrons get the the kinetic energy from the voltage applied across the conductor

6 0
2 years ago
Read 2 more answers
A small metal sphere has a mass of 0.19 gg and a charge of -23.0 nCnC. It is 10.0 cmcm directly above an identical sphere that h
RoseWind [281]

Answer:

  a = -7.29 m / s²

Explanation:

For this exercise we must use Newton's second law,

          F -W = m a

Force is electrical force

         F = k q₁ q₂ / r²

         k q₁ q₂ / r² -mg = m a

indicate that the charge of the two spheres is equal

         q₁ = q₂ = q

         a = (k q² / r² - m g) / m

         a = k q² / m r² - g

Let's reduce the magnitudes to the SI system

        m = 0.19 g (1kg / 1000 g) = 1.9 10⁻⁴ kg

        q1 = q2 = q = -23.0 nC (1C / 10⁹ nC) = -23.0 10⁻⁹ C

        r = 10.0 cm (1m / 100cm) = 0.1000 m

let's calculate

        a = 9 10⁹ (23.0 10⁻⁹)² / (0.1000² 1.9 10⁻⁴) - 9.8

        a = -7.29 m / s²

The negative sign indicates that the direction of this acceleration is downward

6 0
2 years ago
A ball is whirled on the end of a string in a horizontal circle of radius R at constant speed v. Complete the following statemen
Eva8 [605]

Answer:

Keeping the speed fixed and decreasing the radius by a factor of 4

Explanation:

A ball is whirled on the end of a string in a horizontal circle of radius R at constant speed v. The centripetal acceleration is given by :

a=\dfrac{v^2}{R}

We need to find how the "centripetal acceleration of the ball can be increased by a factor of 4"

It can be done by keeping the speed fixed and decreasing the radius by a factor of 4 such that,

R' = R/4

New centripetal acceleration will be,

a'=\dfrac{v^2}{R'}

a'=\dfrac{v^2}{R/4}

a'=4\times \dfrac{v^2}{R}

a'=4\times a

So, the centripetal acceleration of the ball can be increased by a factor of 4.

7 0
3 years ago
Please I really need the help
Lunna [17]

Answer:

7) there is a theory that these animals can see the magnetic field of the Earth due to a compass like mechanism inside their eyes in order to navigate.

8) Earth's magnetic field is a result of the currents found inside the outer core that consist of electricity.

3 0
3 years ago
Other questions:
  • Feng and Isaac are riding on a merry-go- round. Feng rides on a horse at the outer rim of the circular platform, twice as far fr
    14·1 answer
  • Is a lipid known as an enzyme
    5·1 answer
  • PLSSS HELP 10 MORE MINS LEFT UNTIL THIS IS DUE The diagram shows you the direction heat energy is moving. Based on the diagram,
    5·1 answer
  • An object exhibits SHM with an angular frequency w = 4.0 s-1 and is released from its maximum displacement of A = 0.50 m at t =
    8·1 answer
  • Parallax error occurs when the observer records data when he/she is at an angle to the event he/she is observing. Where do you t
    13·1 answer
  • How does the constitution protect the rights of individuals against vivo
    11·1 answer
  • Connie flew from Phoenix to flagstaff, a distance of 180 miles at a constant speed of 180 miles per hour. She then returned to t
    6·1 answer
  • Imma straight male btw also wut are newtons law write a paragraph desricbing them
    10·1 answer
  • I need an answer quick
    13·1 answer
  • This is an image of a satellite traveling around Earth. Explain what are the two forces that are keeping the satelite around Ear
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!