Final answer:
When the distance between two masses is quintupled, the gravitational force becomes 1/25 of the original force due to the inverse square law. In this case, the new force is 20N.
Step-by-step explanation:
The force of gravitation between two masses is directly proportional to the product of the two masses and inversely proportional to the square of the distance between them. This is represented by Newton's law of universal gravitation, which is often formulated as F = G (m1*m2) / r^2, where F is the gravitational force, G is the gravitational constant, and r is the distance between the centers of the two masses.
When the distance between two masses is increased by a factor of five, the new distance is five times the original distance. Therefore, according to the inverse square law, the gravitational force will decrease by a factor of 5 squared, which is 25. If the original force is 500N, the new force will be 500N/25, giving us a new gravitational force of 20N.
The correct answer to the question, 'The force of gravitation between two masses is 500N. If the masses are moved five times as far apart, what is their new force of gravitational attraction?' is option (a) 20N.