Answer:

Explanation:
v = Orbital speed = 130 km/s
d = Diameter = 16 ly
r = Radius = 
G = Gravitational constant = 6.67 × 10⁻¹¹ m³/kgs²

As the centripetal force balances the gravitational energy we have the following relation

Mass of the the massive object at the center of the Milky Way galaxy is 
Answer:
K.E₂ = mg(h - 2R)
Explanation:
The diagram of the car at the top of the loop is given below. Considering the initial position of the car and the final position as the top of the loop. We apply law of conservation of energy:
K.E₁ + P.E₁ = K.E₂ + P.E₂
where,
K.E₁ = Initial Kinetic Energy = (1/2)mv² = (1/2)m(0 m/s)² = 0 (car initially at rest)
P.E₁ = Initial Potential Energy = mgh
K.E₂ = Final Kinetic Energy at the top of the loop = ?
P.E₂ = Final Potential Energy = mg(2R) (since, the height at top of loop is 2R)
Therefore,
0 + mgh = K.E₂ + mg(2R)
<u>K.E₂ = mg(h - 2R)</u>
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