How does surface tension relate to the molecular structure of water

A heavy solid disk rotating freely and slowed only by friction applied at its outer edge takes 120 seconds to come to a stop.

alisha [4.7K]

Answer:

The time is 16 min.

Explanation:

Given that,

Time = 120 sec

We need to calculate the moment of inertia

Using formula of moment of inertia

$I=\dfrac{1}{2}MR^2$

If the disk had twice the radius and twice the mass

The new moment of inertia

$I'=\dfrac{1}{2}\times2M\times(2R)^2$

$I'=8I$

We know,

The torque is

$\tau=F\times R$

We need to calculate the initial rotation acceleration

Using formula of acceleration

$\alpha=\dfrac{\tau}{I}$

Put the value in to the formula

$\alpha=\dfrac{F\times R}{\dfrac{1}{2}MR^2}$

$\alpha=\dfrac{2F}{MR}$

We need to calculate the new rotation acceleration

Using formula of acceleration

$\alpha'=\dfrac{\tau}{I'}$

Put the value in to the formula

$\alpha=\dfrac{F\times R}{8\times\dfrac{1}{2}MR^2}$

$\alpha=\dfrac{2F}{8MR}$

$\alpha=\dfrac{\alpha}{8}$

Rotation speed is same.

We need to calculate the time

Using formula angular velocity

$\Omega=\omega'$

$\alpha\time t=\alpha'\times t'$

Put the value into the formula

$\alpha\times120=\dfrac{\alpha}{8}\times t'$

$t'=960\ sec$

$t'=16\ min$

Hence, The time is 16 min.

5 0

3 years ago

What is the terminal velocity of blood? A. 8.9 feet/seconds B. 9.8 feet/seconds C. 25.1 feet/second D. 52.1 feet/seconds

goblinko [34]

Answer:

the answer is c) 25.1 feet/second

Explanation:

because the blood droplets can not increase speed past terminal velocity 100.

3 0

3 years ago

What is the tension in the string if the turntable is held fixed, with the mass hanging from the pulley (i. e. , the mass is sta

Paladinen [302]

Weight of the mass is the tension in the string if the turntable is held fixed, with the mass hanging from the pulley

Weight is a force that acts at all times on all objects near Earth. The Earth pulls on all objects with a force of gravity downward toward the center of the Earth. Weight (symbolized w ) is a quantity representing the force exerted on a particle or object by an acceleration field, particularly the gravitational field of the Earth at the surface.

The tension force is defined as the force that is transmitted through a rope, string or wire when pulled by forces acting from opposite sides. The tension force is directed over the length of the wire and pulls energy equally on the bodies at the ends.

The direction of tension is the pull which is given the name tension. Thus, the tension will point away from the mass in the direction of the string/rope. In case of the hanging mass, the string pulls it upwards, so the string/rope exerts an upper force on the mass and the tension will be in the upper side.

Tension will act opposite the the weight of the mass attached in order to maintain equilibrium .

To learn more about weight here

brainly.com/question/2293244

#SPJ4

7 0

2 years ago

in a football game, the kicker kicks a football a horizontal distance of 43 yards if the ball lands 3.9 seconds later, what is t

erica [24]

Answer:

10s

Explanation:

7 0

3 years ago

The position of an ant and a spider in a room are A(2,3,5) and B(6,0,8) determine the distance

marta [7]

Answer:

$|d| = \sqrt{ {(x_{2} -x_{1})}^{2} + {(y_{2} -y_{1})}^{2} + {(z_{2} -z_{1})}^{2}} \\ = \sqrt{ {(6 - 2)}^{2} + {(3 - 0)}^{2} +{(5 - 8)}^{2} } \\ = \sqrt{16 + 9 + 9} \\ = \sqrt{34}$

4 0

3 years ago