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3 years ago

The diagram below shows the layers of a rock having a trilobite. which statement about the rock fossils is true?

Physics

1 answer:

emmainna [20.7K]3 years ago

3 0

Actually the greatest information we can extract from the graph is that the lower the fossil is located beneath the rock, the older it is. So we can see that fossil A is the oldest, trilobite and fossil B came together, and fossil C is the youngest. From the choices, the answer is:

D. fossil B belongs to the same period as the trilobite

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The angular momentum of a flywheel having a rotational inertia of 0.142 kg·m2 about its central axis decreases from 7.20 to 0.14

luda_lava [24]

Answer:

3.3619 Nm

54.27472 rad

182.46618 J

86.88 W

Explanation:

$L_i$ = Initial angular momentum = 7.2 kgm²/s

$L_f$ = Final angular momentum = 0.14 kgm²/s

I = Moment of inertia = 0.142 kgm²

t = Time taken

Average torque is given by

$\tau_{av}=\frac{L_f-L_i}{\Delta t}\\\Rightarrow \tau_{av}=\frac{0.14-7.2}{2.1}\\\Rightarrow \tau_{av}=-3.3619\ Nm$

Magnitude of the average torque acting on the flywheel is 3.3619 Nm

Angular speed is given by

$\omega_i=\frac{L_i}{I}$

Angular acceleration is given by

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

From the equation of rotational motion

$\theta=\omega_it+\frac{1}{2}\alpha t^2\\\Rightarrow \theta=\frac{L_i}{I}\times t+\frac{1}{2}\times \frac{\tau}{I}\times t^2\\\Rightarrow \theta=\frac{7.2}{0.142}\times 2.1+\frac{1}{2}\times \frac{-3.3619}{0.142}\times 2.1^2\\\Rightarrow \theta=54.27472\ rad$

The angle the flywheel turns is 54.27472 rad

Work done is given by

$W=\tau\theta\\\Rightarrow W=-3.3619\times 54.27472\\\Rightarrow W=-182.46618\ J$

Work done on the wheel is 182.46618 J

Power is given by

$P=\frac{W}{t}\\\Rightarrow P=\frac{-182.46618}{2.1}\\\Rightarrow P=-86.88\ W$

The magnitude of the average power done on the flywheel is 86.88 W

6 0

2 years ago

Part A What is the resistance of a 4.4 m length of copper wire 1.3 mm n diameter? The resistivity of copper is 1.68x 10-8 Ω-m Ex

Natalija [7]

Explanation:

It is given that,

Length of the copper wire, l = 4.4 m

Diameter of copper wire, d = 1.3 mm = 0.0013 m

Radius of copper wire, r = 0.00065 m

The resistivity of the copper wire, $\rho=1.68\times 10^{-8}\ \Omega-m$

We need to find the resistance of the copper wire. It is given by :

$R=\rho\dfrac{l}{A}$

$R=1.68\times 10^{-8}\ \times \dfrac{4.4\ m}{\pi (0.00065)^2}$

R =0.055 ohms

So, the resistance of the copper wire is 0.055 ohms. Hence, this is the required solution.

7 0

2 years ago

Sarah's group designed this oven and eventually melted the

torisob [31]

Answer:

Explanation:

because i don't he asking me

5 0

3 years ago

The latent heat of fusion for Aluminium is 3.97 x 105. How much energy would be required to melt 0.75 kg of it?

RoseWind [281]

Answer:

$E = 2.9775\times10^5 J$

Explanation:

Given: The latent heat of fusion for Aluminum is $L = 3.97\times10^5 J/Kg$

mass to be malted m = 0.75 Kg

Energy require to melt E = mL

$E = 3.97\times10^5\times0.75 = 2.9775\times10^5 J$

Therefore, energy required to melt 0.75 Kg aluminum

$E = 2.9775\times10^5 J$

5 0

2 years ago

Ex 10: My dog runs at 6 m/s for 18 meters. How long did she run for?

Hunter-Best [27]

She ran for 3s

Put 18/6 because in order to find how long she ran for you need to divide the distance by the meters ran, once you do that you will get 3.

7 0

2 years ago