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Readme
1 month ago
5

Two trains are headed towards each other on the same track unbeknownst to the engineers. One departs San Francisco. Its average

speed is 55 miles per hour. The 2nd departs Seattle at the same time that the first one departs San Francisco. Its average speed is 65 miles per hour. The length of track separating the two locations is 860 miles. How many minutes (from departure time) before the two trains collide?
Physics
1 answer:
ValentinkaMS [3.4K]1 month ago
7 0

Answer:

7.166 hours = 430 minutes.

Explanation:

As both trains are approaching each other on the same track, their relative speed is the sum of their individual speeds. Hence, the time until they intersect (and inevitably collide) is determined by how long it takes for speeds of 65 mph and 55 mph to cover the total distance of 860 miles. One train will cover part of the distance, while the other will cover the remainder. To calculate the required time, we can apply the formula:

1 hour ---> 120 miles

X ----> 860 miles; hence X = (860 miles * 1 hour)/120 miles = 43/6 hours = 7.16666 hours. To convert this into minutes, recall that 1 hour equals 60 minutes; therefore, 43/6 hours * 60 minutes/hour = 430 minutes.

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kicyunya [3294]
For motion in a circle.

Centripetal acceleration is calculated as mv²/r = mω²r

where v represents linear velocity, r equals radius which is diameter/2 equating to 1/2 or 0.5m

. Here, m is the mass of the object, which is 175g or 0.175kg.

The angular speed, ω, is derived from Angle covered / time

                         = 2 revolutions per 1 second

                         = 2 * 2π  radians for each second

                         = 4π  radians per second

Thus, Centripetal Acceleration = mω²r = 0.175*(4π)² * 0.5. Utilize a calculator

                                                         ≈13.817  m/s²

. The acceleration's magnitude is approximately 13.817  m/s² and it is oriented towards the center of the circular path.

The tension in the string equates to m*a

                                   = 0.175*13.817

                                   = 2.418 N
5 0
29 days ago
Read 2 more answers
An object initially at rest experiences a constant horizontal acceleration due to the action of a resultant force applied for 10
inna [3103]

Answer:

a = 18.28 ft/s²

Explanation:

the values provided are:

duration of force application, t= 10 s

Work done = 10 Btu

mass of the object = 15 lb

acceleration, a =? ft/s²

1 Btu = 778.15 ft.lbf

thus, 10 Btu = 7781.5 ft.lbf

m = \dfrac{15}{32.174}\ slug

m = 0.466 slug

So,

the work is equivalent to the change in kinetic energy

W = \dfrac{1}{2} m (v_f^2-v_i^2)

7781.5 = \dfrac{1}{2}\times 0.466\times v_f^2

 v_f = 182.75\ ft/s

The acceleration of the object is therefore

  a = \dfrac{v_f-v_o}{t}

  a = \dfrac{182.75-0}{10}

         a = 18.28 ft/s²

the constant acceleration of the object is calculated to be 18.28 ft/s²

3 0
1 month ago
You are standing at the midpoint between two speakers, a distance D away from each. The speakers are playing the exact same soun
ValentinkaMS [3465]

Answer:

Explanation:

The wavelength of sound can be calculated using the formula: wavelength = velocity / frequency.

Thus, it becomes:

λ = 340 / 170

λ = 2 m.

When the person stands ideally in the center between the speakers, the sound waves reaching him are perfectly aligned (no path difference), resulting in maximum sound intensity.

As he moves closer to one of the speakers, his proximity to that speaker increases while the distance to the other speaker decreases, creating a path difference in the sound waves reaching his ears.

If he walks 0.5 m toward one speaker, the created path difference becomes:

0.5 x 2 = 1 m.

This path difference equals λ / 2, leading to destructive interference, resulting in minimal sound being audible.

As he continues walking a full 1 m, the created path difference totals 2 m.

This corresponds to a path difference of λ, causing constructive interference and maximum sound perception.

Finally, if he moves an additional 1.5 m, the resulting path difference increases to 3 m.

Thus, we arrive at a path difference of 3 λ / 2, producing destructive interference once more, leading to minimum sound being perceived again.

In summary, the man begins at a maximum intensity point, moves to minimum intensity, then back to a maximum, and ultimately ends at another minimum sound intensity position.

3 0
1 month ago
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serg [3582]

Provided Information:

Length of inclined plane = 8 m

Height of inclined plane = 2 m

Weight of the ice block = 300 N

Required Information:

Force needed to push ice block = F =?

Answer:

Force needed to push the ice block = 75 N

Explanation:

The required force to push this ice block up an inclined plane is given by

F = Wsinθ

where W is the weight of the ice block and θ is the angle indicated in the attached image.

Using trigonometric ratios,

sinθ = opposite/hypotenuse

where the opposite side is the height of the inclined plane and the hypotenuse is the length of the inclined plane.

Thus, sinθ = 2/8

θ = sin⁻¹(2/8)

which leads to θ = 14.48°

Therefore, F = 300*sin(14.48)

results in F = 75 N

This indicates that a force of 75 N is necessary to push the ice block on the specified inclined plane.

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Yuliya22 [3333]

Answer: t = 0.878s

Explanation: A note for you,

since the temperature decreases in a straight line, you can expect the movement speed to also behave linearly. However, this isn't exactly true (referring to the formula). Alternatively, utilize the interpolation principle: (x/v_surface + x/v_top)/2 = t.

While the answer may not match exactly, it should be a close approximation. You can use this formula, thus avoiding large distance calculations.

7 0
2 months ago
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