Answer:
F=0
Explanation:
Newton's second law states that the sum of the external forces is equal to the product of the mass and the acceleration of the body
F = m a
in this case it tells us that the velocity is constant so the acceleration must be zero,
therefore the sum of the external forces is zero; as they indicate that the surface is frictionless, there is no force applied to the system to maintain a constant speed
F = 0
It's because the gravity on the moon is 1/6th the Earth's gravity
Answer:

Explanation:
Let's assume that an object is launched straight upward in a gravitational field. Its initial kinetic energy is given by
(1)
where m is the mass and v is the initial speed.
As the object goes higher, its kinetic energy decreases and it is converted into gravitational potential energy, since the total mechanical energy (sum of kinetic and potential energy) must remain constant:

At the highest point of the trajectory, the speed of the object is zero (v=0), so the kinetic energy is also zero (K=0), which means that all the kinetic energy has been converted into potential energy:
(2)
where g is the gravitational acceleration and h is the maximum height of the object.
Due to conservation of energy, we can write that (1) and (2) are equal, so:

from which we can derive an expression for the maximum height reached by the object

Let’s say you’re hitting the golf ball with a golf club. Therefore, using the 3rd law to explain it... the golf ball will hit the club back. The reason why the ball moves, is because it can only sustain a certain amount of force.
Here’s another example:
https://physics.stackexchange.com/questions/150335/newtons-third-law-and-punching-a-glass-or-a-feather