What two units of measure are necessary for describing speed

A student places an object with a mass of m on a disk at a position r from the center of the disk. The student starts rotating t

koban [17]

Answer:

The coefficient of static friction between the object and the disk is 0.087.

Explanation:

According to the statement, the object on the disk experiments a centrifugal force due to static friction. From 2nd Newton's Law, we can represent the object by the following formula:

$\Sigma F_{r} = \mu_{s}\cdot N = m\cdot \frac{v^{2}}{R}$ (1)

$\Sigma F_{y} = N - m\cdot g = 0$ (2)

Where:

$N$ - Normal force from the ground on the object, measured in newtons.

$m$ - Mass of the object, measured in newtons.

$g$ - Gravitational acceleration, measured in meters per square second.

$v$ - Linear speed of rotation of the disk, measured in meters per second.

$R$ - Distance of the object from the center of the disk, measured in meters.

By applying (2) on (1), we obtain the following formula:

$\mu_{s}\cdot m\cdot g = m\cdot \frac{v^{2}}{R}$

$\mu_{s} = \frac{v^{2}}{g\cdot R}$

If we know that $v = 0.8\,\frac{m}{s}$ , $g = 9.807\,\frac{m}{s^{2}}$ and $R = 0.75\,m$ , then the coefficient of static friction between the object and the disk is:

$\mu_{s} = \frac{\left(0.8\,\frac{m}{s} \right)^{2}}{\left(9.807\,\frac{m}{s^{2}} \right)\cdot (0.75\,m)}$

$\mu_{s} = 0.087$

The coefficient of static friction between the object and the disk is 0.087.

5 0

3 years ago

Two cars, one of mass 1300 kg, and the second of mass 2400 kg, are moving at right angles to each other when they collide and st

Margarita [4]

To solve this problem we will apply the momentum conservation theorem, that is, the initial momentum of the bodies must be the same final momentum of the bodies. The value that will be obtained will be a vector value of the final speed of which the magnitude will be found later. Our values are given as,

$m_1 = 1300kg$

$m_2 = 2400kg$

$u_1 = 12m/s i$

$u_2 = 18m/s j$

Using conservation of momentum,

$m_1u_1+m_2u_2 = (m_1+m_2)v_f$

$1300*12i-2400*18j = (1300+2400)v_f$

Solving for $v_f$

$v_f = 4.2162i-11.6756j$

Using the properties of vectors to find the magnitude we have,

$|v| = \sqrt{(4.2162^2)+(-11.6756)^2}$

$|v| = 12.4135m/s$

Therefore the magnitude of the velocity of the wreckage of the two cars immediately after the collision is 12.4135m/s

6 0

3 years ago

What can you infer about an object moving at a constant velocity

Dmitry [639]

the object has kinetic energy, because it is on the move!!

8 0

3 years ago

Which phase occurs between the new moon and the first quarter?

Igoryamba

Answer:

waxing gibbous moon

It comes a week after new moon. A waxing gibbous moon occurs when more than half of the lit portion of the Moon can be seen and the shape increases ("waxes") in size from one day to the next. The waxing gibbous phase occurs between the first quarter and full moon phases.

4 0

3 years ago

Which shows a decrease in fluid pressure? A. Water in a creek slows down as it enters a slow-moving river. B. Oxygen is compress

Ainat [17]

Answer:

Option D.

A fan is turned from high speed to low speed.

Explanation:

It is important to note that air is also a fluid.

In a system, static pressure of air increases with the speed of rotation of the fan. This is because when the speed of the fan is increased, the force with which it is pushing the air molecules is increased. Since pressure is a relationship between force and area, the pressure of the air molecules will be increased.

Conversely, when the speed of the fan is reduced, the priming force on the air molecules will be reduced, hence the pressure of the air will drop.

This makes option D the correct option

3 0

3 years ago

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