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ad-work [718]
2 years ago
6

(c) A moving train has a kinetic energy of 8.1 x 10(power of 6)J.

Physics
1 answer:
tamaranim1 [39]2 years ago
8 0

the friction force provided by the brakes is 30000 N.

<h3>What is friction force?</h3>

Friction force is the force that opposes the motion between two bodies in contact.

To calculate the average friction force provided by the brakes, we apply the formula below.

Formula:

  • K.E = F'd............. Equation 1

Where:

  • K.E = Kinetic energy of the train
  • F' = Friction force provided by the brakes
  • d = distance

Make F' the subject of the equation

  • F' = K.E/d............ Equation 2

From the question,

Given:

  • K.E = 8.1×10⁶
  • d = 270 m

Substitute these values into equation 2

  • F' = (8.1 ×10⁶)/270
  • F' = 30000 N

Hence, the friction force provided by the brakes is 30000 N

Learn more about friction force here: brainly.com/question/13680415

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A molecular cloud fragments as it collapses because Choose one: A. the interstellar wind is stronger in some places than others.
kondaur [170]

The cause for a molecular cloud forming fragments when it collapses is indicated correctly by option D. density variations from place to place grow larger as the cloud collapses.

Molecular cloud:

A molecular cloud, also known as a stellar nursery, is a specific kind of interstellar cloud, whose density and size allow the development of molecules, absorption nebulae, and H II regions. In contrast, some regions of the interstellar medium mostly consist of ionized gas.

Molecular clouds are cold, dense areas of space where stars form. The cloud collapses into a proto-star when the gravitational force pulling it in outweighs the internal pressure pushing it in.

When a molecular cloud collapses, it is observed that the density varies from place to place with the variation increasing with collapse. As a result, the collapse is characterized by fragmentation of the cloud.

Thus the correct option is: D. density variations from place to place grow larger as the cloud collapses.

Learn more about molecular clouds,

brainly.com/question/3459894

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6 0
1 year ago
The coefficient of kinetic friction between a suitcase and the floor is 0.272. You may want to review (Pages 196 - 203) . Part A
vazorg [7]

Answer:

Explanation:

The work required to push will be equal to work done by friction . Let  d be the displacement required .

force of friction = mg x μ where m is mass of the suitcase , μ be the coefficient of friction

work done by force of friction

mg x μ x d   = 660

80 x 9.8 x .272 x d = 660

d = 3 .1 m .

8 0
2 years ago
For the simple harmonic motion equation
My name is Ann [436]
Given that : d = 5sin(pi t/4), So, maximum displacement, d = 5*(+1) = 5 Also, maximum displacement, d = 5*(-1) = -5 
3 0
3 years ago
According to the navigation rules, which must be aboard a 22-foot powerboat
melomori [17]
The navigation rules for countries in the Unites States are compiled in the U.S. Coast Guard. There are actually boating courses that are recognized by the U.S Coast Guard. One of the things they discuss there is the emergency aids every boat should have depending on the size and purpose. For recreational vessels with lengths measuring less than 39.4 feet, they must carry aboard an efficient sound producing device. This will serve as your signal when emergencies happen and you have to get the attention of nearby boat vessels. Hence, for practical purposes, every boat should have a whistle or a horn.
4 0
2 years ago
A piano string having a mass per unit length equal to 4.70 10-3 kg/m is under a tension of 1 400 N. Find the speed with which a
sweet [91]

Answer:

The speed of the sound wave on the string is 545.78 m/s.

Explanation:

Given;

mass per unit length of the string, μ = 4.7 x 10⁻³ kg/m

tension of the string, T = 1400 N

The speed of the sound wave on the string is given by;

v = \sqrt{\frac{T}{\mu} }

where;

v is the speed of the sound wave on the string

Substitute the given values and solve for speed,v,

v = \sqrt{\frac{T}{\mu} }\\\\v = \sqrt{\frac{1400}{4.7*10^{-3}} }\\\\v = \sqrt{297872.34}\\\\v = 545.78 \ m/s

Therefore, the speed of the sound wave on the string is 545.78 m/s.

3 0
2 years ago
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