Knowing that 1 hour is 60 minutes and that she got 10 km in 45 i doubt shes gonna run another 12 km in 15 minutes and the answer has to be atleast 10km so i would say your answer is "d. 13km/hr"
None of the choices is correct.
== The Earth's radius is 6,371 km. That's how far you are from the center of the Earth when you're on the ground.
== The acceleration of gravity on the ground is 9.8 m/s² .
== The acceleration of gravity varies inversely as the square of the distance from the center of the Earth. So, at 7,200 km from the center, it's
(9.8 m/s²) · (6371km/7200km)² .
Stuffing this through your cakulator, you'll get <em>7.67 m/s²</em> .
