A car travels 50km east east in 30 min what is its velocity in km/h

A large turntable with radius 6.00 m rotates about a fixed vertical axis, making one revolution in 8.00 s. The moment of inertia

yanalaym [24]

Answer:

0.8024

Explanation:

From the given question; we can say that the angular momentum of the system is conserved if the net torque is is zero.

So; $I_o \omega _o = I_2 \omega_2$

At the closest distance ; the friction is :

$f_s = \mu_s (mg)$

According to Newton's Law:

F = ma

F = mrω²

From conservation of momentum:

$I_o \omega _o = I_2 \omega_2$

$\omega_2= \frac { I_o \omega _o}{ I_2 }$

$\omega_2=( \frac { I_1+ mr_o^2}{ I_1 + mr^2 })* \omega_o$

However ; since the static friction is producing the centripetal force :

$\mu_s (mg) = mr \omega_2^2$

$\mu _s = \frac{ \omega^2_2 *r }{g}$

The coefficient of static friction between the bottoms of your feet and the surface of the turntable can now be calculated by using the formula :

$\mu _s = \frac{ \omega^2_2 *r }{g}$

= $( \frac { I_1+ mr_o^2}{ I_1 + mr^2 })^2 * \frac{ \omega^2_o *r }{g}$

= $[\frac{1200+(73(6)^2)}{((1200)+(73)(3)^2)} ]^2*[\frac{(\frac{\pi}{4})^2(3)} {9.8}]$

= 0.8024

4 0

3 years ago

A child holds onto a string attached to a toy boat and exerts a force of 7.5 N to pull the boat a distance of 9.2 m a long a str

soldi70 [24.7K]

The work that need to do is 66.24 J.

<h3>Explanation :</h3>

Hello guys, before we can count how much the work that needed to pull the toy, we should know how formula to count it first. Because the movement is with the angle, so the formula is :

$\boxed {\bold {W = F \times s \times \cos(\theta)}}$

If :

W = work (J)
F = force (N)
s = shift (m)
θ = elevation angle (°)

We know that :

x = the horizontal shift = 9,2 m
θ = elevation angle = 15°

W = work = ... J

$W = F \times s \times \cos(\theta) \\ W = 7.5 \times 9.2 \times \cos(15) \\ W = 69 \times 0.96 = 66.24 \: J$

So, the work that need to do is 66.24 J.

Subject : Physics 

Class : Junior High School/Senior High School 

Keyword : Work; Force; Shift; and Elevation Angle 

5 0

4 years ago

20 POINTS TRUE OR FALSE:

romanna [79]

False because the first law of motion is the crash I think I’m in middle school

8 0

3 years ago

In order for work to be done a___ must be exerted on an object causing it to___

Fed [463]

In order for work to be done a force must be exerted on an object causing it to move

8 0

2 years ago

The practice of playing top hits several times a day on radio stations is called _____. blocking rotation circulation format dri

spin [16.1K]

The practice of playing top hits several times a day on radio stations is called rotation.

7 0

3 years ago

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