The gravitational force f exerted by the earth on an object having a mass of 100 kg is given by the equationf = 4,000,000d2where d is the distance (in km) of the object from the center of the earth, and the force f is measured in newtons (n). for what distances (in km) will the gravitational force exerted by the earth on this object be between 0.000625 n and 0.0025 n? (enter your answer using interval notation.)

We want to calculate distance of the object to the center of the earth for which gravitational force is equal to 0.000625 N and 0.0025 N Note: correction in the formula given otherwise have no sense, because gravitational force is higher when distance is near to earth and weaker when object goes away, that means force and distance are inversely proportional. So then we need to solve the given equation for these values: F = 4000000/d^2 => d = (4000000/F)^1/2 = (4000000/0.000625)^1/2 = 80,000 km F = 4000000/d^2 => d = (4000000/F)^1/2 = (4000000/0.0025)^1/2 = 40,000 km So then the gravitational force is between 0.000625 N and 0.0025 N when : 40,000 <= d <= 80,000 km

It’s either a or c as the answer.