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Mice21 [21]
3 years ago
5

Two metra trains approach each other on separate but parallel tracks. one has a speed of 90 km/hr, the other 80 km/hr. initially

, the two trains are 2.71 km apart. how long will it take the two trains to pass each other?
Physics
1 answer:
Gennadij [26K]3 years ago
6 0

The trains take <u>57.4 s</u> to pass each other.

Two trains A and B move towards each other. Let A move along the positive x axis and B along the negative x axis.

therefore,

v_A=90 km/h\\ v_B=-80 km/h

The relative velocity of the train A with respect to B is given by,

v_A_B=v_A-v_B\\ =(90km/h)-(-80km/h)\\ =170km/h

If the train B is assumed to be at rest, the train A would appear to move towards it with a speed of 170 km/h.

The trains are a distance d = 2.71 km apart.

Since speed is the distance traveled per unit time, the time taken by the trains to cross each other is given by,

t= \frac{d}{v_A_B}

Substitute 2.71 km for d and 170 km/h for v_A_B

t= \frac{d}{v_A_B}\\ =\frac{2.71 km}{170 km/h} \\ =0.01594 h

Express the time in seconds.

t=(0.01594h)(3600s/h)=57.39s

Thus, the trains cross each other in <u>57.4 s</u>.

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kakasveta [241]

Answer:

0.63 s

Explanation:

From the question given above, the following data were obtained:

Mass (m) = 50 g

Extention (e) = 10 cm

Period (T) =?

Next, we obtained 50 g to Kg. This can be obtained as follow:

1000 g = 1 Kg

Therefore,

50 g = 50 g × 1 Kg / 1000 g

50 g = 0.05 kg

Next, we shall convert 10 cm to m. This is illustrated below:

100 cm = 1 m

Therefore,

10 cm = 10 cm × 1 m / 100 cm

10 cm = 0.1 m

Next, we shall determine the force exerted on the spring. This can be obtained as follow:

Mass = 0.05 Kg

Acceleration due to gravity (g) = 9.8 m/s²

Force (F) =?

F = mg

F = 0.05 × 9.8

F = 0.49 N

Next, we shall determine the spring constant of the spring.

Extention (e) = 0.1 m

Force (F) = 0.49 N

Spring constant (K) =?

F = Ke

0.49 = K × 0.1

Divide both side by 0.1

K = 0.49 /0.1

K = 4.9 N/m

Finally, we shall determine the period as follow:

Mass = 0.05 Kg

Spring constant (K) = 4.9 N/m

Pi (π) = 3.14

Period (T) =?

T = 2π√(m/k)

T = 2 × 3.14 × √(0.05 / 4.9)

T = 6.28 × √(0.05 / 4.9)

T = 0.63 s

Thus, the period of oscillation is 0.63 s

4 0
3 years ago
A beaker of vegetable oil contains a beam of light that is aimed at a surface at an angle of 34 degrees as shown. If the index o
OverLord2011 [107]

Answer:

Angle of reflection of light is 34 degree

Explanation:

As per law of reflection of light we know that

angle of incidence of light = angle of reflection of light

So here we know that

angle of incidence on the surface of oil is given as

\theta_i = 34 degree

so we know that

\theta_i = \theta_r

so here we can say that reflection angle of light will be same as angle of incidence

\theta_r = 34 degree

8 0
3 years ago
Draw an atom of Aluminum, use your book to find the Atomic number and the mass.
7nadin3 [17]

Answer:

Solution

The atomic number of iodine (53) tells us that a neutral iodine atom contains 53 protons in its nucleus and 53 electrons outside its nucleus. Because the sum of the numbers of protons and neutrons equals the mass number, 127, the number of neutrons is 74 (127 − 53 = 74). Since the iodine is added as a 1− anion, the number of electrons is 54 [53 – (1–) = 54].

Check Your Learning

An ion of platinum has a mass number of 195 and contains 74 electrons. How many protons and neutrons does it contain, and what is its charge?

Answer:

78 protons; 117 neutrons; charge is 4+

5 0
3 years ago
The concept that large masses warp the shape of spacetime and thus change the path of an object moving through that spacetime ap
mrs_skeptik [129]

Answer: Newton's law of gravity theory disagrees with Einstein's theory. The last one were named Theory of General Relativity and was discovered and proposed by the physicist Einstein in the year of 1915.

Explanation: Until the beginning of 20 century, the physics were ruled by Isaac Newton's ideas. He believed that the gravity was a force caused by the objects mass on the space, made them to be draw towards each other. Newton thought that the greater the mass of the object, the more intense was its attraction, which would justify the planet's moovements around the sun and how the gravity between them maintain the planets on solar orbit. Concluding, he believed gravity was a immediate force of action, regardless of the distance of the bodies.

Contrary to Newton's law of gravity, in 1915, the physicist Einstein created the Theory of General Relativity, wich discovered that gravity was, in fact, the deformation caused by the attraction of massive celestial bodies. This deformation, related to the Sun, for example, creates a curvature on the space-time and this curvature are followed by the other planets.

So, we can conclude that Newton's law of gravity disagree's with the Theory of General Relativity, once the first believes that light force of attraction are transmitted instantly and, as Einstein already prooved, the gravity influency propagates in the speed of light.

4 0
3 years ago
Chocolate milk contains more than one type of component. Therefore, it 1 point
crimeas [40]

Answer:

Homogeneous.

Explanation:

Mixture can be defined as a combination of two or more substances present in varied proportion where each materials are distinct and visibly seen by naked eyes.

In Science, there are two (2) main types of mixture and these are;

I. A homogeneous mixture: it can be defined as any liquid, solid or gaseous mixture which has an identical or uniform composition and properties throughout any given sample of the mixture. In Chemistry, all solutions are considered to be a homogeneous mixture. For example, aqueous hydrogen chloride is a homogeneous mixture of water and hydrogen chloride.

II. A heterogenous mixture: it can be defined as any mixture which has a different or non-uniform composition and properties throughout any given sample of the mixture. This ultimately implies that, the constituents of a heterogenous mixture always remain separate in the sample and as such comprises of two or more phases.

Since the chocolate milk contains more than one type of component. Therefore, it is not a homogeneous substance but a heterogenous substance.

6 0
3 years ago
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