An arrow of mass 20 g is shot horizontally into a bale of hay, striking the hay with a velocity of 60 m/s. It penetrates a depth of 20 cm before stopping. What is the average stopping force acting on the arrow?
At a distance of 14000 km from some planet’s center, the acceleration of gravity is 32 m/s^2. What is the acceleration of gravity at a point 28000 km from the planet’s center?