Help with Force

[buffgilville]

A ball of mass 1.6 kilograms is projected with a velocity 16.6 m/s in a direction 74.7 degrees from the horizontal. The acceleration due to gravity is g = 9.81 m/s2. What is the force acting on the ball when it is at the uppermost point in its orbit?

Since the force due to gravity is essentially constant close to the earth's surface, does that mean the force acting on the ball is 15.696 Newtons? or is it 9.81 Newtons?

[HallsofIvy]

"F= ma". Since you are given that m= 1.6 kg and g= 9.81 m/s2, yes, the force is 15.696 Newtons (actually, I would say -15.696 Newtons but, then, I would have used -9.81 m/s2 for g).
That's a very peculiar question! You are given a lot of extraneous information and the force is the same, the weight of the object, no matter where in its trajectory it is. (I also would not use the word "orbit" here!)