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3 years ago

The graph below describes the journey of a train between two cities

Mathematics

2 answers:

vovangra [49]3 years ago

8 0

Answer:

200km/h^2, 125km, 62.5km/h

Step-by-step explanation:

For part a) just use the acceleration formula (change in velocity/time). For part b), remember that distance traveled is the area under the graph. This is because displacement is the integral of velocity, meaning that you integrate to find the area (i.e. displacement). Lastly, for part c), just apply speed = distance/time because in this case, acceleration is constant.

UkoKoshka [18]3 years ago

3 0

Answer:

Step-by-step explanation:

To find : Acceleration in first 15 min . Distance between two cities Average speed of journey

Solution:

Each horizontal block is 1/8 hr = 7.5 min

Each vertical block is 10 km/hr

Time Velocity km/hr

0 Min ( 0 hr) 0

15 Min (1/4 hr) 50

45 Min (3/4 hr) 50

60 MIn ( 1 hr) 100

90 Min ( 3/2 hr) 100

120 Min ( 2hr) 0

Acceleration in first 15 min (1/4 hr) = (50 - 0)/(1/4 - 0) = 50/(1/4)

= 200 km/h²

Distance between two cities

= (1/2)(0 + 50)(1/4 - 0) + 50 * (3/4 - 1/4) + (1/2)(50 + 100)(1 - 3/4) + 100 * (3/2 - 1) + (1/2)(100 + 0)(2 - 3/2)

= 25/4 + 25 + 75/4 + 50 + 25

= 125

Distance between two cities = 125 km

Average Speed of journey = 125/2 = 62.5 km/hr

Acceleration in first 15 min = 200 km/h²

Distance between two cities = 125 km

Average Speed of journey = 62.5 km/hr

Hope this helps..

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vredina [299]

Answer:

$x = 49.8^\circ\\y = 54.6^\circ$

Step-by-step explanation:

Kindly refer to the image attached in the answer region for labeling of triangle.

AB = 16

BC = 19

AC = 15

$\angle ABC = x^\circ\\\angle ACB = y^\circ$

We have to find the angles x and y i.e. $\angle B \text{ and }\angle C$ .

Formula for cosine rule:

$cos B = \dfrac{a^{2}+c^{2}-b^{2}}{2ac}$

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Similarly, for finding the value of y:

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3 years ago

If the seed company recommends planting approximately 350 grass seeds per square meter, about how many grass seeds will he need?

Svetach [21]

Answer:

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Step-by-step explanation:

Applying,

A = 1/2bh....................... Equation 1

Where A = Area of the Triangle, b = base, h = height.

But, from the diagram,

tanФ = 20/b

b = 20/tanФ.................. Equation 2

Substitute equation 2 into equation 1

A = 1/2(20/tanФ)(h)................ Equation 3

Given: h = 20 m, Ф = 40°

Substitute these values into equation 3

A = 1/2(20×20)/tan40°

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A = 238.35 m²

If the seed company recommends planting approximately 350 grass seeds per square meter,

Therefore,

Number of grass seed need = (350×238.35)

Number of grass seed needed = 83422.5 grass seeds

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3 years ago

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Kaylis [27]

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3 years ago

Please help I have no idea how to do this!

Alexus [3.1K]

Answer:

D. <B = 141°

Step-by-step explanation:

The sum of interior angles of a polygon is

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Sum of angles for our polygon that has 7 sides must be:

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<B = 900 -759 = 141°

Check our work:

120°+129°+130°+142°+90°+148°+ 141° = 900°✅

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