A person covers a distance of 320 miles in a travel time of 8 hours. What is the speed for this trip?

An airplane flying at a speed of 130 mi/h (58.1 m/s) and at an altitude of 4.9 km drops a food package. Without a parachute, at

telo118 [61]

The food package will strike the ground at 11 degrees below the horizontal.

<h3>Time for the food package to hit the ground</h3>

The time for the food package to hit the ground is calculated as follows;

h = vt + ¹/₂gt²

<em>let the initial velocity be horizontal</em>

4900 = 0(t) + (0.5 x 9.8)t²

4900 = 4.9t²

t² = 4900/4.9

t² = 1,000

t = √1,000

t = 31.62 s

<h3> Final speed of the food package when it hits ground</h3>

vf(y) = vo + gt

vf(y) = 0 + (31.62 x 9.8)

vf(y) = 309.88 m/s

<h3>Angle of projection</h3>

The horizontal component of the speed will be constant, while vertical component will change

$tan(\theta ) = \frac{V_y}{V_x} \\\\\theta = tan^{-1} (\frac{V_y}{V_x})\\\\\theta = tan^{-1} (\frac{309.88}{58.1} )\\\\\theta = 79^0$

Angle below the horizontal = 90 - 79 = 11⁰

Thus, the food package will strike the ground at 11 degrees below the horizontal.

Learn more about angle of projection here: brainly.com/question/10671136

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2 years ago

A 15 m ladder with a mass of 51 kg is leaning against a frictionless wall, which makes an angle of 60 degrees with the horizonta

timofeeve [1]

Answer:

Explanation:

Given that, .

Mass of ladder is 51kg

Then, it weight is

WL = mg = 51 × 9.81 = 500.31N

This weight will act at the midpoint of the ladder

Length of ladder is 15m

The ladder makes an angle 55°C with the horizontal

An object whose mass is 81kg is at 4m from the bottom of the ladder

Then, weight of object

Wo = mg = 81 × 9.81 = 794.61 N

Using newton second law

Check attachment

Ng is normal force on the ground

Ff is the horizontal frictional force

Nw Is the normal force on the wall

ΣFy = 0

Ng = Wo + WL

Ng = 794.61 + 500.31

Ng = 1294.92 N

Also

ΣFx = 0

Ff — Nw = 0

Then,

Ff = Nw

Now taking moment about point A.

Check attachment

using the principle of equilibrium

Sum of clockwise moment equals to sum of anti-clockwise moment

Also note that the Normal force on the wall is not perpendicular to the ladder, so we will resolve that and also the weights of ladder and weight of object

Clockwise = Anticlockwise

Wo•Cos60 × 4 + WL•Cos60 × 7.5 = Nw•Sin60 × 15

794.61Cos60 × 4 + 500.31Cos60 × 7.5 = Nw × Sin60 × 15

1589.22 + 1876.163 = 12.99•Nw

3465.383 = 12.99•Nw

Nw = 3465.383 / 12.99

Nw = 266.77 N

Since, Nw = Ff

Then, Ff = 266.77N

the horizontal force exerted by the ground on the ladder is 266.77 N

8 0

3 years ago

Read 2 more answers

What is a mixture in science class

Veseljchak [2.6K]

A mixture is 2 or more different elements not bonded together
Example : N2 or O2

6 0

3 years ago

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CAN AIR MAKE SHADOWS?

Tems11 [23]

Answer:

No because you cannot see air so therefore it cannot make shadows

Explanation:

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3 years ago

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A glass rod and a steel rod are of equal length at 0C. At 100C they differ in length by

NeX [460]

The given lengths at 0 °C are 2.5 m

Let l₀ be the given lengths of the glass and steel rods at 0 °C. Let l and l' be the lengths of the glass and steel rods at 100 °C respectively.

From our expression for linear expansivity,

l = l₀ + l₀αΔθ where α = linear expansivity of glass = 0.000008/°C and Δθ = temperature change = θ - θ' where θ = 100 °C and θ' = 0 °C. So, Δθ = 100 °C - 0 °C = 100 °C.

Also,

l' = l₀ + l₀α'Δθ where α' = linear expansivity of steel = 0.000012/°C and Δθ = temperature change = θ - θ' where θ = 100 °C and θ' = 0 °C. So, Δθ = 100 °C - 0 °C = 100 °C.

Since the difference in their lengths at 100 °C = 0.001 m, we have that

l - l' = l₀ + l₀αΔθ - (l₀ + l₀α'Δθ)

l - l' = l₀ + l₀αΔθ - l₀ - l₀α'Δθ)

l - l' = l₀αΔθ - l₀α'Δθ

l - l' = l₀(α- α')Δθ

Making l₀ subject of the formula, we have

l₀ = (l - l')/[(α- α')Δθ]

Substituting the values of the variables into the equation, we have

l₀ = (l - l')/[(α- α')Δθ]

l₀ = 0.001 m/[(0.000008/°C - 0.000012/°C)100 °C.]

l₀ = 0.001 m/[(-0.000004/°C)100 °C.]

l₀ = 0.001 m/-0.0004

l₀ = -2.5 m

Neglecting the negative sign,

l₀ = 2.5 m

So, the given lengths at 0 °C are 2.5 m

Learn more about linear expansion here:

brainly.com/question/14089545

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2 years ago