Answer:
The escape speed of a planet is the minimum speed that an object needs to attain to escape the gravitational pull of the planet and not fall back. Since the meteor's speed is less than the escape speed of Planet Zoroaster, it will not escape and will crash into the planet.
To find the final speed of the meteor when it hits the surface of the planet, we can use the principle of conservation of energy. At a great distance from the planet, the meteor has only kinetic energy. As it approaches the planet, its potential energy increases due to the planet's gravitational attraction, while its kinetic energy decreases due to the planet's gravitational deceleration.
At the moment of impact, all of the meteor's kinetic energy will be converted into other forms of energy (such as heat and sound) upon hitting the surface. Therefore, we can equate the initial kinetic energy of the meteor to the sum of its potential energy and its final kinetic energy just before impact.
Initial kinetic energy = 1/2 * m * v1^2
where m is the mass of the meteor and v1 is its initial speed.
Potential energy at the surface of the planet = -G * M * m / R
where G is the gravitational constant, M is the mass of the planet, m is the mass of the meteor, and R is the radius of the planet.
Final kinetic energy just before impact = 1/2 * m * v2^2
where v2 is the final speed of the meteor just before impact.
We can set these equal and solve for v2:
1/2 * m * v1^2 = -G * M * m / R + 1/2 * m * v2^2
Simplifying and solving for v2, we get:
v2 = sqrt(2 * G * M / R + v1^2)
Plugging in the given values, we get:
v2 = sqrt(2 * 6.6743 × 10^-11 m^3 kg^-1 s^-2 * M / 5 × 10^6 m + (5.0 km/s)^2)
where M is the mass of Planet Zoroaster.
Without knowing the mass of Planet Zoroaster, we cannot determine the exact value of v2. However, we can use the given escape speed to find the mass of the planet:
escape speed = sqrt(2 * G * M / R)
=> M = R * escape speed^2 / (2 * G)
Plugging in the given values, we get:
M = 5 × 10^6 m * (12.0 km/s)^2 / (2 * 6.6743 × 10^-11 m^3 kg^-1 s^-2) = 3.599 × 10^25 kg
Now we can calculate the final speed of the meteor:
v2 = sqrt(2 * 6.6743 × 10^-11 m^3 kg^-1 s^-2 * 3.599 × 10^25 kg / 5 × 10^6 m + (5.0 km/s)^2) ≈ 12.032 km/s
Therefore, the meteor will be moving at a speed of approximately 12.032 km/s when it hits the surface of Planet Zoroaster.