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Gennadij [26K]
3 years ago
14

If a subway train is moving to the left (has a negative velocity) and then comes to a stop, what is the direction of its acceler

ation? Is the acceleration positive or negative?
Physics
1 answer:
Katen [24]3 years ago
8 0

Answer:

The acceleration would be positive, pointing to the right.

Explanation:

The acceleration tells us how velocity changes every second. If the train stops, this means its velocity must go from a non-zero value to zero.

To reduce velocity, acceleration must point to the opposite direction. Since velocity is negative, acceleration must be positive.

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Both independent and dependent clauses
Assoli18 [71]

Answer: have a subject and a verb

Explanation:

5 0
3 years ago
Read 2 more answers
A new planet is discovered beyond Pluto at a mean distance to the sun of 4004 million miles. Using Kepler's third law, determine
AVprozaik [17]

Answer:

103239.89 days

Explanation:

Kepler's third law states that the square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit.

                               a³ / T² = 7.496 × 10⁻⁶  (a.u.³/days²)

where,

a is the distance of the semi-major axis in a.u

T is the orbit time in days

Converting the mean distance of the new planet to astronomical unit (a.u.)

                       1 a.u = 9.296 × 10⁷ miles        

                                      \frac{4004 * 10^{6}}{9.296 * 10^{7}}  =  43.07\ a.u.

Substituting the values into Kepler's third law equation;

                                    \frac{(43.07)^{3}}{T^{2}}  =  7.496 * 10^{-6}  

                                    T^{2} = \frac{(43.07)^{3}}{7.496 * 10^{-6}} (days)²

                                    T^{2} = \sqrt{\frac{(43.07)^{3}}{7.496 * 10^{-6}}}

                                    T = 103239.89 days

An estimate time T for the new planet to travel around the sun in an orbit is 103239.89 days

7 0
3 years ago
A person is standing on and facing the front of a stationary skateboard while holding a construction brick. The mass of the pers
Inessa [10]

Answer:

    v₁ = -0.8087 m / s

Explanation:

To solve this problem we can use the conservation of momentum, for this we define a system formed by the man, the skateboard and the brick, therefore the force during the separation is internal and the momentum is conserved

Initial instant. When they are united

        p₀ = 0

Final moment. After throwing the brick

        p_{f} = (m_man + m_skate) v1 + m_brick v2

the moment is preserved

        p₀ = p_{f}

        0 = (m_man + m_skate) v₁ + m_brick v₂

        v₁ = -  \frac{ m_{brick}   }{m_{man} + m_{skate}   }  v_{2}

the negative sign indicates that the two speeds are in the opposite direction

let's calculate

        v₁ = - \frac{2.5}{67 + 4.10}  23.0

        v₁ = -0.8087 m / s

6 0
3 years ago
Which of the following statements is true of the strong nuclear force?
vredina [299]

Explanation:

it holds protons and neutrons together

5 0
3 years ago
Use the passage to answer the question.
Studentka2010 [4]

This is not something that waves do because they need a medium to travel through, while particles do not.

<h3>How light travels in space?</h3>

A light travels without any medium while on the other hand, a medium is required for sound waves to move from oe place to another. Sound is a mechanical wave that cannot travel through a vacuum.

So we can conclude that electromagnetic waves like light do not require medium for its propagation.

Learn more about light here: brainly.com/question/19697218

3 0
1 year ago
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