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Burka [1]
3 years ago
11

What's a Blackhole ?​

Physics
1 answer:
Vlad1618 [11]3 years ago
7 0

Answer:

A black hole is a region of spacetime where gravity is so strong that nothing—no particles or even electromagnetic radiation such as light—can escape from it. The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole.

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Usually, large amount of curent flows in a<br> Circuit due to two reasons ———— and ————.
omeli [17]

Answer:

Explanation:

Possible causes for overcurrent include short circuits, excessive load, incorrect design, an arc fault, or a ground fault. Fuses, circuit breakers, and current limiters are commonly used overcurrent protection (OCP) mechanisms to control the risks

please  

Brain-list it or support me at my U-Tube channel " ZK SOFT&GAMING " I will be thankful

8 0
3 years ago
The block in the drawing has dimensions L0×2L0×3L0,where L0 =0.5 m. The block has a thermal conductivity of 200 J/(s·m·C˚). In d
Dennis_Churaev [7]

Answer:

Q_p=18000\ J

Q_o=8000\ J

Q_g=72000\ J

Explanation:

Given:

  • Length of block, l=3L_o=3\times 0.5=1.5\ m
  • Breadth of block, b=L_o=0.5\ m
  • height of block, h=2L_o=2\times 0.5=1\ m
  • Thermal conductivity of the block, k=200\ W.m.^{\circ}C
  • Temperature on the hotter side, T_H=37^{\circ}C
  • temperature on the cooler side, T_L=7^{\circ}C
  • time for which the heat flows, t=4\ s

<u>REFER THE ATTACHED IMAGE FOR THE REFERENCE</u>

<em>The rate of heat flow using </em><em>Fourier's law</em><em> of conduction is given as:</em>

\frac{Q}{t}=k.A.\frac{dT}{dx}

<u>Now the amount heat flow perpendicular to the pink surface:</u>

\frac{Q_p}{4}=200\times (0.5\times 1.5).\frac{30}{1}

Q_p=18000\ J

<u>Now the amount heat flow perpendicular to the orange surface:</u>

\frac{Q_o}{4}=200\times (0.5\times 1).\frac{30}{1.5}

Q_o=8000\ J

<u>Now the amount heat flow perpendicular to the green surface:</u>

\frac{Q_g}{4}=200\times (1.5\times 1).\frac{30}{0.5}

Q_g=72000\ J

6 0
4 years ago
What are two components that make up force?
Sveta_85 [38]
The answer is mass and acceleration
6 0
4 years ago
Read 2 more answers
A ball falls from the top of a building. As it falls, its speed increases. Which type of energy is the ball gaining as it falls?
Elina [12.6K]
<h2>Hello!</h2>

The answer is: B. Kinetic energy

<h2>Why?</h2>

Since the ball is falling, speed increases because the gravity acceleration is acting. When speed increases, the kinetic energy increases too, so the ball is gaining kinetic energy.

The gravity acceleration is equal to 9.81\frac{m}{s^{2}}, it means that when falling, the ball will increase it's speed 9.81m every second.

We can calculate the kinetic energy by using the following formula:

KE=\frac{1}{2}*m*v^{2}

Where:

m=mass\\v=velocity

Have a nice day!

<h2 />
5 0
4 years ago
You are an engineer helping to design a roller coaster that carries passengers down a steep track and around a vertical loop. Th
vova2212 [387]

Answer:

h >5/2r

Explanation:

This problem involves the application of the concepts of force and the work-energy theorem.

The roller coaster undergoes circular motion when going round the loop. For the rider to stay in contact with the cart at all times, the roller coaster must be moving with a minimum velocity v such that at the top the rider is in a uniform circular motion and does not fall out of the cart. The rider moves around the circle with an acceleration a = v²/r. Where r = radius of the circle.

Vertically two forces are acting on the rider, the weight and normal force of the cart on the rider. The normal force and weight are acting downwards at the top. For the rider not to fall out of the cart at the top, the normal force on the rider must be zero. This brings in a design requirement for the roller coaster to move at a minimum speed such that the cart exerts no force on the rider. This speed occurs when the normal force acting on the rider is zero (only the weight of the rider is acting on the rider)

So from newton's second law of motion,

W – N = mv²/r

N = normal force = 0

W = mg

mg = ma = mv²/r

mg = mv²/r

v²= rg

v = √(rg)

The roller coaster starts from height h. Its potential energy changes as it travels on its course. The potential energy decreases from a value mgh at the height h to mg×2r at the top of the loop. No other force is acting on the roller coaster except the force of gravity which is a conservative force so, energy is conserved. Because energy is conserved the total change in the potential energy of the rider must be at least equal to or greater than the kinetic energy of the rider at the top of the loop

So

ΔPE = ΔKE = 1/2mv²

The height at the roller coaster starts is usually higher than the top of the loop by design. So

ΔPE =mgh - mg×2r = mg(h – 2r)

2r is the vertical distance from the base of the loop to the top of the loop, basically the diameter of the loop.

In order for the roller coaster to move smoothly and not come to a halt at the top of the loop, the ΔPE must be greater than the ΔKE at the top.

So ΔPE > ΔKE at the top. The extra energy moves the rider the loop from the top.

ΔPE > ΔKE

mg(h–2r) > 1/2mv²

g(h–2r) > 1/2(√(rg))²

g(h–2r) > 1/2×rg

h–2r > 1/2×r

h > 2r + 1/2r

h > 5/2r

5 0
3 years ago
Read 2 more answers
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