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
Dvinal [7]
3 years ago
12

A diver can reduce her moment of inertia by a factor of about 3.5 when changing from the straight position to the tuck position.

If she makes two rotations in 1.5 seconds when in the tuck position, what is her angular speed (rad/sec) when in the straight position?
Physics
1 answer:
katovenus [111]3 years ago
4 0

Answer:

29.3 rad/s

Explanation:

Moment of inertia in straight position, I1 = I

He takes 2 rotations in 1.5 second

So, Time period, T = 1.5 / 2 = 0.75 second

w1 = 2 x 3.14 / T = 2 x 3.14 / 0.75 = 8.37 rad/s

Moment of inertia in tucked position, I2 = I / 3.5

Let the new angular speed is w2.

By the use of conservation of angular momentum, if no external torque is applied, then angular momentum is constant.

L1 = L2

I1 w1 = I2 w2

I x 8.37 = I / 3.5 x w2

w2 = 29.3 rad/s

You might be interested in
In the mobile m1=0.42 kg and m2=0.47 kg. What must the unknown distance to the nearest tenth of a cm be if the masses are to be
LuckyWell [14K]

Complete Question

The complete question is shown on the first uploaded image

Answer:

Explanation:

From he question we are told that

    The first mass is   m_1 = 0.42kg

      The second mass is  m_2 = 0.47kg

From the question we can see that at equilibrium the moment about the point where the  string  holding the bar (where m_1 \ and \ m_2 are hanged ) is attached is zero  

   Therefore we can say that

               m_1 * 15cm  = m_2 * xcm

Making x the subject of the formula  

                x = \frac{m_1 * 15}{m_2}

                    = \frac{0.42 * 15}{0.47}

                     x = 13.4 cm

Looking at the diagram we can see that the tension T  on the string holding the bar where m_1  \  and   \ m_2 are hanged  is as a result of the masses (m_1 + m_2)

     Also at equilibrium the moment about the point where the string holding the bar (where (m_1 +m_2)  and  m_3 are hanged ) is attached is  zero

   So basically

          (m_1 + m_2 ) * 20  = m_3 * 30

          (0.42 + 0.47)  * 20 = 30 * m_3

 Making m_3 subject

          m_3 = \frac{(0.42 + 0.47) * 20 }{30 }

                m_3 = 0.59 kg

3 0
3 years ago
Which transformation of energy occurs when a fan is turned on and the blades start to rotate?
Ksju [112]

Answer:

kinetic energy

Explanation:

A wind turbine transforms the mechanical energy of wind into electrical energy. A turbine takes the kinetic energy of a moving fluid, air in this case, and converts it to a rotary motion. As wind moves past the blades of a wind turbine, it moves or rotates the blades. These blades turn a generator

5 0
3 years ago
A 60kg student traveling in a 1000kg car with a constant velocity has a kinetic energy of 1.2 x 10^4 J. What is the speedometer
777dan777 [17]

Answer:

17.64 km/h

Explanation:

mass of car, m = 1000 kg

Kinetic energy of car, K = 1.2 x 10^4 J

Let the speed of car is v.

Use the formula for kinetic energy.

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

By substituting the values

1.2\times 10^{4} = \frac{1}{2}\times 1000\times v^{2}

v = 4.9 m/s

Now convert metre per second into km / h

We know that

1 km = 1000 m

1 h = 3600 second

So, v = \left (\frac{4.9}{1000}   \right )\times \left ( \frac{3600}{1} \right )

v = 17.64 km/h

Thus, the reading of speedometer is 17.64 km/h.

4 0
3 years ago
According to the Big Bang Theory, how long ago did the universe expand explosively into existence
Dmitry_Shevchenko [17]

About 13.7 billion years ago

The Big Bang Theory states that the universe started about 13.7 billion years ago, and before that, everything was in 1 singularity.



3 0
3 years ago
Read 2 more answers
Where is the magnetic field of a horseshoe magnet the strongest?<br> pls hellp omg
Nuetrik [128]
The answer is slightly left and slightly right of the curved end of the horseshoe.
7 0
3 years ago
Read 2 more answers
Other questions:
  • A strong lightning bolt transfers an electric charge of about 16 C to Earth (or vice versa). How many electrons are transferred?
    6·1 answer
  • 50 POINTS ANSWER CORRECTLY
    11·2 answers
  • Change the following sentences into Passive Voice: (5M)
    15·1 answer
  • A box falls off of a tailgate and slides along the street for a distance of 62.5 m. Friction slows the box at –5.0 m/s2. At what
    8·1 answer
  • 8. A point of Charge +3.0 X 10^-7 Coulomb is placed 2.0 X 10^-2 from a second
    15·1 answer
  • An initially motionless test car is accelerated uniformly to 120 km/h in 8.28 s before striking a simulated deer. The car is in
    15·1 answer
  • If the index of refraction of a lens is 1.5, how fast does light travel in the lens?
    14·2 answers
  • How can electricity be compared to water?
    13·1 answer
  • A train is traveling at a speed of 80\,\dfrac{\text{km}}{\text{h}}80 h km ​ 80, start fraction, start text, k, m, end text, divi
    9·2 answers
  • What would be the coefficient of performance if the refrigerator (operating between the same temperatures) was instead used as a
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!