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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 car travels with a velocity 16m/s and accelerates 5m/s^2. Calculate the final velocity when it has travelled 36.9m
marissa [1.9K]

v²=u²+2as

v²=16²+2×5×36.9

v²=625

√v²=√625

v=25

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4 0
3 years ago
Acid rain is the direct result of acid released by burning fossil fuels. T/F
disa [49]

Answer : False.

Explanation : Acid rain is the indirect result of burning fossil fuels. As the incomplete combustion of fossil fuels releases sulfur dioxide and nitrous dioxide in the air. When it rains it gets mixed with water and forms nitric acid and sulfuric acid which causes acid rain. Acid rain is harmful.

7 0
3 years ago
Read 2 more answers
David is driving a steady 30.0 m/s when he passes Tina, who is sitting in her car at rest. Tina begins to accelerate at a steady
SpyIntel [72]

Answer:

Explanation:

Let after time t , Tina catches up David .

Distance travelled by them are equal ,

Distance travelled by Tina

s = ut + 1/2 a t²

= .5 x 2.10 t²

= 1.05 t²

Distance travelled by David

= 30 t ( because of uniform velocity )

1.05 t² = 30t

t = 28.57 s

Distance travelled by Tina

= 1/2 a t²

= .5 x 2.10 x 28.57²

= 857 m approx.

7 0
3 years ago
Read 2 more answers
2. Two identical conducting spheres are placed with their centers 0.30 m apart. One is given a charge of 12 x 10-9 C and the oth
Maru [420]

Answer:

A. -2.16 * 10^(-5) N

B. 9 * 10^(-7) N

Explanation:

Parameters given:

Distance between their centres, r = 0.3 m

Charge in first sphere, Q1 = 12 * 10^(-9) C

Charge in second sphere, Q2 = -18 * 10^(-9) C

A. Electrostatic force exerted on one sphere by the other is:

F = (k * Q1 * Q2) / r²

F = (9 * 10^9 * 12 * 10^(-9) * -18 * 10^(-9)) / 0.3²

F = -2.16 * 10^(-5) N

B. When they are brought in contact by a wire and are then in equilibrium, it means they have the same final charge. That means if we add the charges of both spheres and divided by two, we'll have the final charge of each sphere:

Q1 + Q2 = 12 * 10^(-9) + (-18 * 10^(-9))

= - 6 * 10^(-9) C

Dividing by two, we have that each sphere has a charge of -3 * 10^(-9) C

Hence the electrostatic force between them is:

F = [9 * 10^9 * (-3 * 10^(-9)) * (-3 * 10^(-9)] / 0.3²

F = 9 * 10^(-7) N

7 0
3 years ago
An airplane starts from rest and accelerates at 10.8 m/s2 . what is its speed at the end of a 400 m long runway?
Cloud [144]

The final speed of an airplane is v = 92.95 m/s

The rate of change of position of an object in any direction is known as speed i.e. in other word, Speed is measured as the ratio of distance to the time in which the distance was covered.

Solution-

Here given,

Acceleration a= 10.8 m/s2 .

Displacement (s)= 400m

Then to find final speed of airplane v=?

Therefore from equation of motion can be written as,

v²=u²+ 2as

where, u is initial speed, v is final speed ,a is acceleration and s is displacement of the airplane. Therefore by putting the value of a & s in above equation and (u =0) i.e. the initial speed of airplane is zero.

v²= 2×10.8 m/s²×400m

v²=8640m/s

v=92.95m/s

hence the final speed of airplane v =92.95m/s

To know more about speed

brainly.com/question/13489483

#SPJ4

5 0
2 years ago
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