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Svetllana [295]

2 years ago

15

a pulley of radius 0.9m is used to lift a bucket from the well. if it took 3.6 rotations for the pulley to take water out of the

well,how deep is water in the well?

1 answer:

Alex777 [14]2 years ago

6 0

Answer:

h = 20.36[m]

Explanation:

To solve this problem we must calculate the perimeter (length of a circumference) of the circumference, which is denoted by the following equation:

L = 2*π*r

where:

r = radius = 0.9[m]

π = 3.1416

L = 2*(3.1416)*(0.9)

L = 5.654[m]

Now we know that the pulley or circumference had to rotate 3.6 times to get the water out of the well. In this way the depth of the well can be calculated by means of the following equation:

h = 3.6*L

h = 3.6*5.654

h = 20.36[m]

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A uniform Rectangular Parallelepiped of mass m and edges a, b, and c is rotating with the constant angular velocity ω around an

Sonbull [250]

Answer:

(a) k = $\frac{Mw^{2} }{6} (a^{2} +b^{2} )$

(b) τ = $\frac{M}{3} (a^{2} +b^{2} )$ ∝

Explanation:

The moment of parallel pipe rotating about it's axis is given by the formula;

I = $\frac{M}{3} (a^{2} +b^{2} )$ ---------------------------------1

(a) The kinetic energy of a parallel pipe is also given as;

k = $\frac{1}{2} Iw^{2}$ --------------------------------2

Putting equation 1 into equation 2, we have;

k = $\frac{M}{6} (a^{2} +b^{2} )w^{2}$

k = $\frac{Mw^{2} }{6} (a^{2} +b^{2} )$

(b) The angular momentum is given by the formula;

τ = Iw -----------------------3

Putting equation 1 into equation 3, we have

τ = $\frac{Mw}{3} (a^{2} +b^{2} )$

But

τ = dτ/dt = $\frac{M}{3} (a^{2} +b^{2} )\frac{dw}{dt}$ ------------------4

where

dw/dt = angular acceleration =∝

Equation 4 becomes;

τ = $\frac{M}{3} (a^{2} +b^{2} )$ ∝

8 0

2 years ago

You are using a lightweight rope to pull a sled along level ground. The sled weighs 485 N, the coefficient of kinetic friction b

Bogdan [553]

Answer:

$N=459.01N$

Explanation:

According to Newton's first law:

$N+F_y-W=0$

The component of the force on the y-axis can be obtained through the Pythagorean Theorem. This is because the components are the cathetus of a right triangle and its hypotenuse is the magnitude of the force:

$sin12^\circ=\frac{F_y}{F}\\F_y=Fsin12^\circ$

Replacing and solving for N:

$N=W-Fsin12^\circ\\N=485N-(125N)sin12^\circ\\N=459.01N$

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2 years ago

an object having a core temperature of 1700 is removed from a furnace and placed in an environment having a constant temperature

IRINA_888 [86]

Answer: It will be take 2.6 hours

Explanation: Please see the attachments below

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2 years ago

A "biconvex" lens is one in which both surfaces of the lens bulge outwards. Suppose you had a biconvex lens with radii of curvat

Stolb23 [73]

Answer: f=150cm in water and f=60cm in air.

Explanation: Focal length is a measurement of how strong light is converged or diverged by a system. To find the variable, it can be used the formula:

$\frac{1}{f}$ = (nglass - ni)( $\frac{1}{R1}$ - $\frac{1}{R2}$ ).

nglass is the index of refraction of the glass;

ni is the index of refraction of the medium you want, water in this case;

R1 is the curvature through which light enters the lens;

R2 is the curvature of the surface which it exits the lens;

Substituting and calculating for water (nwater = 1.3):

$\frac{1}{f}$ = (1.5 - 1.3)( $\frac{1}{10}$ - $\frac{1}{15}$ )

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f = $\frac{30}{0.2}$ = 150

For air (nair = 1):

$\frac{1}{f}$ = (1.5 - 1)( $\frac{1}{10}$ - $\frac{1}{15}$ )

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In air, f = 60cm.

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2 years ago

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snow_tiger [21]

Answer:

$2.5 \times 10^{11} N-m$ upwards

Explanation:

Torque is the vector cross product of the force and radial distance.

$\tau = rF sin \theta$

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The direction of the torque would be perpendicular to the direction of the force and radial distance. The direction of the force is counter-clockwise. The direction of the torque would be upwards.

4 0

2 years ago