All categories

3 years ago

A 2.73 kg cylindrical grinding wheel with a radius of 31 cm rotates at 1416 rpm. What is its angular momentum? Answers:

Physics

1 answer:

Nezavi [6.7K]3 years ago

5 0

Answer:

The angular momentum of the wheel is $19.45\ kg-m^2/s$ .

Explanation:

It is given that,

Mass of the wheel, m = 2.73 kg

Radius of the wheel, r = 31 cm = 0.31 m

Angular speed of the wheel, $\omega=1416\ rpm= 148.28\ rad/s$

We need to find its angular momentum. It is given by :

$L=I\omega$

I is the moment of inertia of the wheel, $I=\dfrac{mr^2}{2}$

$L=\dfrac{mr^2}{2}\times \omega$

$L=\dfrac{2.73\times (0.31)^2}{2}\times 148.28$

$L = 19.45\ kg-m^2/s$

So, the angular momentum of the wheel is $19.45\ kg-m^2/s$ . Hence, this is the required solution.

You might be interested in

Why does a balloon stick to a wall questions and problems answers?

Akimi4 [234]

<span>The reason that the balloon will stick to the wall is because the negative charges in the balloon will make the electrons in the wall move to the other side of their atoms and this leaves the surface of the wall positively charged.</span>

7 0

3 years ago

A battery with an emf of 12.0 V shows a terminal voltage of 11.7 V when operating in a circuit with two lightbulbs, each rated a

wariber [46]

<h2>Answer:</h2>

0.46Ω

<h2>Explanation:</h2>

The electromotive force (E) in the circuit is related to the terminal voltage(V), of the circuit and the internal resistance (r) of the battery as follows;

E = V + Ir --------------------(a)

Where;

I = current flowing through the circuit

But;

V = I x Rₓ ---------------------(b)

Where;

Rₓ = effective or total resistance in the circuit.

<em>First, let's calculate the effective resistance in the circuit:</em>

The effective resistance (Rₓ) in the circuit is the one due to the resistances in the two lightbulbs.

Let;

R₁ = resistance in the first bulb

R₂ = resistance in the second bulb

Since the two bulbs are both rated at 4.0W ( at 12.0V), their resistance values (R₁ and R₂) are the same and will be given by the power formula;

P = $\frac{V^{2} }{R}$

=> R = $\frac{V^{2} }{P}$ -------------------(ii)

Where;

P = Power of the bulb

V = voltage across the bulb

R = resistance of the bulb

To get R₁, equation (ii) can be written as;

R₁ = $\frac{V^{2} }{P}$ --------------------------------(iii)

Where;

V = 12.0V

P = 4.0W

Substitute these values into equation (iii) as follows;

R₁ = $\frac{12.0^{2} }{4}$

R₁ = $\frac{144}{4}$

R₁ = 36Ω

Following the same approach, to get R₂, equation (ii) can be written as;

R₂ = $\frac{V^{2} }{P}$ --------------------------------(iv)

Where;

V = 12.0V

P = 4.0W

Substitute these values into equation (iv) as follows;

R₂ = $\frac{12.0^{2} }{4}$

R₂ = $\frac{144}{4}$

R₂ = 36Ω

Now, since the bulbs are connected in parallel, the effective resistance (Rₓ) is given by;

$\frac{1}{R_{X} }$ = $\frac{1}{R_1}$ + $\frac{1}{R_2}$ -----------------(v)

Substitute the values of R₁ and R₂ into equation (v) as follows;

$\frac{1}{R_X}$ = $\frac{1}{36}$ + $\frac{1}{36}$

$\frac{1}{R_X}$ = $\frac{2}{36}$

Rₓ = $\frac{36}{2}$

Rₓ = 18Ω

The effective resistance (Rₓ) is therefore, 18Ω

<em>Now calculate the current I, flowing in the circuit:</em>

Substitute the values of V = 11.7V and Rₓ = 18Ω into equation (b) as follows;

11.7 = I x 18

I = $\frac{11.7}{18}$

I = 0.65A

<em>Now calculate the battery's internal resistance:</em>

Substitute the values of E = 12.0, V = 11.7V and I = 0.65A into equation (a) as follows;

12.0 = 11.7 + 0.65r

0.65r = 12.0 - 11.7

0.65r = 0.3

r = $\frac{0.3}{0.65}$

r = 0.46Ω

Therefore, the internal resistance of the battery is 0.46Ω

5 0

3 years ago

Read 2 more answers

10. Almost three-quarters of household energy use is due to the following:

Arturiano [62]

Answer: Energy consumption and sustainability is important so that it remain available for future generation.

Explanation:

1. The home furnaces are likely to require fuel like coal, which will directly emit carbon dioxide and carbon monoxide gases. These should be replaced with the electrical furnaces. The old or more power consuming air conditioners should be replaced with new ones.

2. The water heaters should be tankless so their capacity to heat more water could be possible. The water heaters should be electricity saving.

3. Washer and dryers should be water savy and electricity savy. A front-loading washing machine is useful energy saver.

4. The LED lights are more electricity saving than conventional bulbs. Halogen lights are also electricity saving.

7 0

3 years ago

What is 0.94kg divided by 2.4n

LuckyWell [14K]

Answer:

0.39166666666

Explanation:

7 0

3 years ago

6.If a 250. gram cart moving to the right with a velocity of .31 m/s collides inelastically with a 500. gram cart traveling to t

spin [16.1K]

Answer:

The total momentum of the system before the collision is 0.0325 kg-m/s due east direction.

Explanation:

Given that,

Mass of the cart, m = 250 g = 0.25 kg

Initial velocity of the cart, u = 0.31 m/s (due right)

Mass of another cart, m' = 500 g = 0.5 kg

Initial velocity of the another cart u' = -0.22 m/s (due left)

Let p is the total momentum of the system before the collision. It is given by :

$p=mu+m'u'\\\\p=0.25\times 0.31+0.5\times (-0.22)\\\\p=-0.0325\ kg-m/s$

So, the total momentum of the system before the collision is 0.0325 kg-m/s due east direction.

5 0

2 years ago

Read 2 more answers