Number 10.6, 10.7 . Please help me

10.6. A particle of mass m in a certain force field given by F = k]? is moving toward the center of the forte. Calculate the time it will take the particle to move from a point at a distance D from the center to the center of the force. 10.7. Suvpse an object is from a height h (h < RE, where RE is the radius of Earth). Show that the speed with which it will hit the ground is