Final answer:
To determine the gravitational constant gₓ on Planet X, we can use the formula F = mg and rearrange it to gₓ = F/m. The force on the rock is 3600 N and the mass is 12 kg, so gₓ = 300 m/s².
Step-by-step explanation:
To determine the gravitational constant gₓ on Planet X, we can use the formula F = mg, where F is the force exerted by the planet, m is the mass of the object, and gₓ is the acceleration due to gravity on Planet X. Rearranging the formula, we have gₓ = F/m.
In this case, the force on the 12 kg rock is given to be 3600 N. So, gₓ = 3600 N / 12 kg = 300 m/s².
Therefore, the correct answer is gₓ = 300 m/s² (option c).