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Yuri [45]
3 years ago
5

Estimate how long it would take one person to mow a football field using an ordinary home lawn mower. suppose that the mower mov

es with a 1-km/h speed, has a 0.5-m width, and a field is 360 ft long and 160 ft wide. 1 m = 3.281 ft.
Physics
1 answer:
HACTEHA [7]3 years ago
4 0
<span>10.7 hours Since we've been told that we have a speed of 1 km/h and a width of 0.5 meters that means that after 1 hour, we can mow a path 0.5 m wide and 1000 m long for a total area of 1000 m * 0.5 m = 500 m^2/hr. Now let's calculate the area of that football field. 360 ft / 3.281 ft/m * 160 ft / 3.281 ft/m = 5350.692864 m^2 Now let's divide that area by the 500 m^2 calculated earlier to see how many hours it will take. 5350.692864 m^2 / 500 m^2/hr = 10.70138573 hr So it would take about 10.7 hours to mow the football field.</span>
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Explanation:

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p = 90 kg m/s

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How to find acceleration?
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The displacement vector A and B when added together , give the resultant vector R so that R= A+B use the data in the drawing and
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The addition of vectors involve both magnitude and direction. In this case, we make use of a triangle to visualize the problem. The length of two sides were given while the measure of the angle between the two sides can be derived. We then assign variables for each of the given quantities.

Let:

b = length of one side = 8 m
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A = angle between b and c = 90°-25° = 75°

We then use the cosine law to find the length of the unknown side. The cosine law results to the formula: a^2 = b^2 + c^2 -2*b*c*cos(A). Substituting the values, we then have: a = sqrt[(8)^2 + (6)^2 -2(8)(6)cos(75°)]. Finally, we have a = 8.6691 m.

Next, we make use of the sine law to get the angle, B, which is opposite to the side B. The sine law results to the formula: sin(A)/a = sin(B)/b and consequently, sin(75)/8.6691 = sin(B)/8. We then get B = 63.0464°. However, the direction of the resultant vector is given by the angle Θ which is Θ = 90° - 63.0464° = 26.9536°.

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5 0
3 years ago
A 10.2-kg mass is located at the origin, and a 4.6-kg mass is located at x = 8.1 cm. Assuming g is constant, what is the locatio
goldfiish [28.3K]

Answer:

center of mass of the two masses will lie at x = 2.52 cm

center of gravity of the two masses will lie at x = 2.52 cm

So center of mass is same as center of gravity because value of gravity is constant here

Explanation:

Position of centre of mass is given as

r_{cm} = \frac{m_1r_1 + m_2r_2}{m_1 + m_2}

here we have

m_1 = 10.2 kg

m_2 = 4.6 kg

r_1 = (0, 0)

r_2 = (8.1cm, 0)

now we have

r_{cm} = \frac{10.2 (0,0) + 4.6 (8.1 , 0)}{10.2 + 4.6}

r_{cm} = {(37.26, 0)}{14.8}

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now for center of gravity we can use

r_g_{cm} = \frac{m_1gr_1 + m_2gr_2}{m_1g + m_2g}

here we have

m_1 = 10.2 kg

m_2 = 4.6 kg

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r_2 = (8.1cm, 0)

now we have

r_g_{cm} = \frac{10.2(9.8) (0,0) + 4.6(9.8) (8.1 , 0)}{10.2(9.8) + 4.6(9.8)}

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r_g_{cm} = (2.52 cm, 0)

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3 0
3 years ago
A drone flies 8 m/s due East with respects to the wind. The wind is blowing 6 m/s due North with respects to the ground. What is
vekshin1

Answer:

B. 10m/s

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√d² = √100

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Hence the distance of the drone with respect to the ground is 10m/s

Option B is correct

8 0
4 years ago
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