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2 years ago

(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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stepan [7]

We can calculate the acceleration of Cole due to friction using Newton's second law of motion:
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Now we can use the following formula to calculate the distance covered by Cole and the sled before stopping:
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3 years ago

parallel-plate air capacitor is made from two plates 0.070 m square, spaced 6.3 mm apart. What must the potential difference bet

Rom4ik [11]

Answer:

V = 576 V

Explanation:

Given:

- The area of the two plates A = 0.070 m^2

- The space between the two plates d = 6.3 mm

- Te energy density u = 0.037 J /m^3

Find:

- What must the potential difference between the plates V?

Solution:

- The energy density of the capacitor with capacitance C and potential difference V is given as:

u = 0.5*ε*E^2

- Where the Electric field strength E between capacitor plates is given by:

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Hence,

u = 0.5*ε*(V/d)^2

Where, ε = 8.854 * 10^-12

V^2 = 2*u*d^2 / ε

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Plug in values:

V = 0.0063*sqrt ( 2 * 0.037 / (8.854 * 10^-12) )

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alukav5142 [94]

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