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3 years ago

14

How long does it take for a rotating object to speed up from 15.0 rad/s to 33.3 rad/s if it has a uniform angular acceleration o

f 3.45 rad/s2

1 answer:

Leona [35]3 years ago

3 0

Answer:

it takes 5.22 seconds

Explanation:

$angular \: acceleration \: = \frac{angular \: velocity}{time}$

t = (33.3 - 15) ÷ 3.45

t = 18 ÷ 3.45

t = 5.22 sec

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During which month is the bacteria population just under 1 million?

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D. March because it is just below the 1 million marker on the graph and it is the only one that low.

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3 years ago

The angle θ is slowly increased. Write an expression for the angle at which the block begins to move in terms of μs.

Reika [66]

Answer:

$tan \theta = \mu_s$

Explanation:

An object is at rest along a slope if the net force acting on it is zero. The equation of the forces along the direction parallel to the slope is:

$mg sin \theta - \mu_s R =0$ (1)

where

$mg sin \theta$ is the component of the weight parallel to the slope, with m being the mass of the object, g the acceleration of gravity, $\theta$ the angle of the slope

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The equation of the forces along the direction perpendicular to the slope is

$R-mg cos \theta = 0$

where

R is the normal reaction

$mg cos \theta$ is the component of the weight perpendicular to the slope

Solving for R,

$R=mg cos \theta$

And substituting into (1)

$mg sin \theta - \mu_s mg cos \theta = 0$

Re-arranging the equation,

$sin \theta = \mu_s cos \theta\\\rightarrow tan \theta = \mu_s$

This the condition at which the equilibrium holds: when the tangent of the angle becomes larger than the value of $\mu_s$ , the force of friction is no longer able to balance the component of the weight parallel to the slope, and so the object starts sliding down.

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4 years ago

The frequency of sound wave A is 250 Hz. Find the time period.

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4 years ago

A solid ball, a solid disk, and a hoop, all with the same mass and the same radius, are set rolling without slipping up an incli

MAXImum [283]

Answer:

d ) is the answer.

Explanation:

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V = ωR

kinetic energy of sphere - 1/2 MV² + 1/2 x 2/5 MR² ω²

= 1/2 MV² + 1/5 MR² ω²

MV² ( 1/2 + 1/5 )

= .7 MV²

kinetic energy of Disk - 1/2 MV² + 1/2 I ω² ,ω is angular velocity and

V = ωR

kinetic energy of Disk - 1/2 MV² + 1/2 x 1/2 MR² ω²

= 1/2 MV² + 1/4 MR² ω²

MV² ( 1/2 + 1/4 )

= .75 MV²

kinetic energy of Hoop - 1/2 MV² + 1/2 I ω² ,ω is angular velocity and

V = ωR

kinetic energy of hoop - 1/2 MV² + 1/2 MR² ω²

= 1/2 MV² + 1/2 MR² ω²

MV² ( 1/2 + 1/2 )

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Kinetic energy is largest in case of hoop and least in case of sphere . So hoop will go up to the highest point and sphere will go to a height which will be least among the three.

7 0

3 years ago

a student wants to push a box of books with the mass of 50 kg in 3 m horizontally towards the location of the shelves where the

irina1246 [14]

Answer:

The work done is 360 J.

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Given that,

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8 0

3 years ago