4. Heat is added to an ideal gas and the gas expands. In such a process the temperature

How much energy is needed to heat 55 Kg of water from 285 K to 360 K?

GalinKa [24]

Answer:

17 kJ

Explanation:

q = mCΔT

q = (55 kg) (4.184 kJ/kg/K) (360 K − 285 K)

q = 17,000 J

8 0

3 years ago

9) A bug of mass 0.020 kg is at rest on the edge of a solid cylindrical disk (M = 0.10 kg, R = 0.10 m) rotating in a horizontal

natima [27]

Answer:

a. ω₂ = 14rad/s

b. ∇K.E = 0.014J

c. The bug does not conserve force while moving on the disk (non-conservative force).

Explanation:

Mass of the bug (m) = 0.02kg

Mass of the cylindrical disk (M) = 0.10kg

Radius of the disk (r) = 0.10m

Initial angular velocity ω₁ = 10rad/s

final angular velocity ω₂ = ?

a.

To calculate the new angular velocity, we relate it to the conservation of angular momentum of the system I.e when the bug was at the edge of the disk and when it is located at the centre of the disk.

I = Mr² / 2

I₁ = Mr₂ / 2 + mr²

I₁ = moment of inertia when the bug was at the edge

I₁ = [(0.10 * 0.10²) / 2 ] + (0.02 * 0.1²)

I₁ = 0.0005 + 0.0002

I₁ = 7.0*10⁻⁴kgm²

I₂ = moment of inertia when yhe bug was at the center of the disk.

I₂ = Mr² / 2

I₂ = (0.01 * 0.01²) 2

I₂ = 0.0005kgm²

for conservation of angular momentum,

I₁ω₁ = I₂ω₂

solve for ω₂

ω₂ = (I₁ * ω₁) / I₂

ω₂ = (7.0*10⁻⁴ * 10) / 5.0*10⁻⁴

ω₂ = 14 rad/s

b. the change in kinetic energy of the system is

∇K = K₂ - K₁

∇K = ½I₂*ω₂² - ½I₁*ω₁²

∇K = ½(I₂*ω₂² - I₁ω₁²)

∇K = ½[(5.0*10⁻⁴ * 14²) - (7.0*10⁻⁴ * 10²)]

∇k = ½(0.098 - 0.07)

∇K = ½ * 0.028

∇K = 0.014J

c.

The cause of the decrease and increase in kinetic energy is because the bug uses a non-conservative force. To conserve the mechanical energy of a system, all the forces acting in it must be conservative.

The work W produced by this force brings the difference in kinetic energy of the system

W = K₂ - K₁

6 0

3 years ago

If a 50microAmps current is flowing then how many electrons pass a point each minute to 2 sig figs? Please add an explanation as

defon

The equation you need to use is $Q=IT$ where Q is the charge in C, I is the current in Amps and T is the time in seconds.

So we have T = 60s
I = $50 \times 10^-^6$ A
let's work out Q
$Q=IT = (50\times 10^{-6}) \times 60 = 3 \times 10^-^3$ C
this is the total charge passing a point in a minute so divide by the charge of one electron ( $1.6 \times 10^{-19}$ ) to find the number of electrons passing the point in a minute which equals $1.875 \times 10^{16}$

6 0

3 years ago

Solve for (b) how many revolutions it takes for the cd to reach its maximum angular velocity in 1.36s?

Digiron [165]

Angular displacement of the cd is 3.25 rev

Explanation:

The question is incomplete. It is not given what is the maximum angular velocity of the cd.

Here we are going to assume that the maximum angular velocity is:

$\omega = 30 rad/s$

The motion of the cd is an accelerated angular motion, therefore we can use the following suvat equation:

$\theta = (\frac{\omega_0 + \omega}{2})t$

where:

$\theta$ is the angular displacement of the cd during the time interval t

$\omega_0$ is the initial angular velocity of the cd

$\omega$ is the final angular velocity

Here we have:

t = 1.36 s

$\omega_0 = 0$ (assuming the cd starts from rest)

Therefore, the angular displacement of the cd during this time is:

$\theta=(\frac{0+30}{2})(1.36)=20.4 rad$

And since $1 rev = 2 \pi rad$ , we can convert into number of revolutions completed:

$\theta = 20.4 rad \cdot \frac{1}{2\pi rad/rev}=3.25 rev$

Learn more about angular motion:

brainly.com/question/9575487

brainly.com/question/9329700

brainly.com/question/2506028

#LearnwithBrainly

8 0

3 years ago

Sever21 [200]

Three units deformations observed in these bands.

<h3>What forces do a rubber band encounter?</h3>

Elastic force is the force that permits some materials to regain their former shape after being stretched or crushed. Thus, a stretched rubber band is subject to an elastic force.

The rubber band experiment uses a straightforward rubber band to show entropic force and a refrigeration cycle. The rubber band experiment involves stretching and then releasing a rubber band while measuring its temperature.

Always acting in the opposite direction of motion is friction. This indicates that if friction is there, it cancels out some of the force driving the motion (if the object is being accelerated). This results in a decreased acceleration and a smaller net force.

learn more about Elastic force refer

brainly.com/question/5055063

#SPJ14

7 0

1 year ago