Planet with a semimajor axis

What is the orbital period (in years) of a planet with a semimajor axis of 10 AU?

Question 2
What is the semimajor axis (in AU) of a planet with an orbital period of 25 years?

Question 3
What is the force of gravity acting between the Earth and a 100-kg person standing on the surface?

Question 4
What is the force of gravity acting between the Earth and a 60-kg person who is 400 km above the surface of the Earth?

Question 5
What is the force of gravity acting between the Sun and a 80-kg person who is 0.8 AU away from the Sun?