What keeps a golf moving once it is hit?

Question

I have a basic understanding of kinetic and potential energy (obviously not enough as will become apparent!)

What I would like to know is after you hit a golf ball (or any other object), what keeps it moving forward? Its not like it has a motor stuff to the back of it, it doesnt expel any rear exhaust thrust.

What is actually moving it?

To help you understand how my mind works, I know why my arm moves and continues to move because I have muscles, a car moves because it has a motor, a fether drops because of gravity.

Hopefully someone can give me a laymans reasons why

Thanks

I already know it is knietic energy...
What I am trying to understand is how is this energy stored in the ball and how does this stored energy keep it moving forward?
A rockets moves in the direction of the jet.
The golf ball moves in the direction it was hit, but what is being expelled in order to keep it moving straight and not in random directions?

Help refine the question more,
If I had a perfect vacuum with no air or other resistances, the ball would continue to move forever, what is keeping it moving?

A great set of answers so far and I am slowly getting but not quite!

I still fail to understand Newton’s first law, WHY does it keep moving once it is moving?

Yes it has kinetic energy but this just feels like a catch all!, what part of this keeps it moving?

If a marble is shot out of a gun in space, it starts moving because of the explosion of the gunpowder, its acceleration and velocity are affected by this until the explosion is unable to affect it any further. This I understand, I also understand why it slows down (resistances etc.), but I still don’t understand why, once the explosion dies, does it would keep moving in space, if it a case that the ball is unable to get rid of its energy? If so, how does this “encapsulated” energy actually keep the ball moving??

Answer 1

The mistake you are making is to think that movement requires energy, when it doesn't. Only changes in movement (acceleration/deceleration) require energy. Once something is moving, it will carry on moving at the same speed and direction without using any energy, unless something is stopping it. In practical terms, the thing stopping it is usually friction, either mechanical friction or wind resistance.

The question is therefore not what makes a golf ball go, but what makes it stop, the answer being air resistance at first, and friction with the grass later.

If you drive very slowly, air resistance is no longer an issue, and car friction is fairly low - if you free wheel in a traffic jam you will find yourself able to go for a surprisingly long way before having to reapply power, when you compare it to taking your foot off the accellerator when you're travelling fast.

EDIT: Part 2, having seen the additional info

Okay, so let me try to explain it this way. Energy is a property of an object in much the same way that mass is a property of an object. If I give energy to an object, it keeps that energy until something acts upon the object to release the energy. According to Newton's laws, the total amount of energy in the system is a constant. You can't add or take away energy, you can only move it around. In the case of your golf ball, for example, when it's travelling through the air, it is transferring some of its energy as heat to the air, a little as sound energy, and a little as kinetic energy to the air molecules. If there wasn't any air, there would be nothing for the golf ball to transfer its energy to, therefore it has to keep it. Kinetic energy is related to mass and velocity, so since the mass of the golf ball isn't changing, and the energy cannot escape, it has to keep the same velocity - if not, energy would be disappearing, and that's impossible according to Newton's laws. The energy the golf ball now has came from the golfer - he burned calories to swing the club and hit the ball. He now has less (mainly chemical) energy in his body than before. If the golf ball hits his playing partner, the energy he provided would be transferred from the ball to the partner, which is why it would be painful.

Is that any better? Email me if not.

Answer 2

1

Answer 3

The answer is Newton’s first law of motion.

Any thing in uniform motion will continue to be in uniform motion.

Any thing in rest will continue to be at rest.

To change the state of rest or state of uniform motion a force is necessary.

Uniform motion means constant velocity or uniform velocity.

Only to increase or decrease the velocity a force is necessary; to keep it in uniform motion no force is necessary.

Once a body is set into a uniform motion no more force is necessary; it will continue to be in uniform motion.

But in practice a force called friction comes into play always and this force brings the body to rest.

If this frictional force is small, the body comes to rest only after moving through a long distance or long time.

In the case of golf ball, the friction is so small that it moves through a long distance before coming to rest.

Any moving body will have velocity (speed) and hence momentum (mass x velocity) and kinetic energy.

The statements that a body is moving, a body is having velocity, a body is having momentum and a body is having kinetic energy are all one and the same.

A body is having kinetic energy means it is moving and vice versa.

In the case of a car or train moving with some constant speed, it is a fact that we are using motor power. But the motor power (force) is just applied to over come the frictional force and not to accelerate the car or train.

If there is no friction between the wheels and road, no motor power is necessary and the car or train once set into motion the engine can be switched off and the train or car will continue to move with constant speed indefinitely.

To stop it we must apply a force from out side.

Once a base ball is hit nothing is needed to keep it moving. In fact it is slowing down due to friction.

Answer 4

G'day Tony Two Sips,

Thanks for your question.

When you hit the ball, you have given it energy. The relevant concept is inertia. The concept of inertia is today most commonly defined using Isaac Newton's First Law of Motion, which states:

Every body perseveres in its state of being at rest or of moving uniformly straight ahead, except insofar as it is compelled to change its state by forces impressed.

The description of inertia presented by Newton's law is still considered the standard for classical physics. However, it has also been refined and expanded over time to reflect developments in understanding of relativity and quantum physics which have led to somewhat different (and more mathematical) interpretations in some of those fields.

On earth, it is the combination of friction with the air and with the ground. If you hit in space, the golf ball would keep going until it was captured by the gravity of another object such as a star, planet or moon.

I attach some sources for further reference.

Regards

Answer 5

It's not a case of continuous propulsion. It begins to slow down immediately after being hit, but due to the length of the club and speed of the swing it starts off going bloody fast.
The knobbly pattern is to make the ball spin while it is travelling which reduces air-resistance.

The effects that slow the ball are air/wind resistance and gravity, which will eventually bring the ball to a stop (with the help of friction when it hits the ground). In effect it doesn't matter whether you hit a golf ball with a club or throw a tennis ball with your hand/arm, it's still the same physical forces at play.

Answer 6

Actually, the golf ball remains absolutely stationary after being hit. It's the rest of the planet that moves in relation to the ball.

The energy imparted by the club causes the ball to accelerate from rest to a velocity (speed and direction) determined by the speed and angle of the club face. It will, as all objects do, continue with that velocity until acted upon by other forces (gravity and wind resistance).

Answer 7

You're thinking about it the wrong way. The question is not why does it keep moving forward, but why does it not stop. It doesn't stop because there is nothing stopping it from moving. Therefore it will keep moving.

You might find it easier to forget that kinetic energy moves it forward. Kinetic energy is something it has because it is moving. When it stops the kinetic energy is transferred to something else (maybe as heat energy), but the kinetic energy doesn't 'push' the ball along.

Answer 8

Inertia and momentum keep it going.

Whilst it seems like nothing is applying a continuous force to it (as with muscle moving your arm), there is actually a continuous force there. Two forces act on it when it's in mid-air: gravity (which wants to make it hit the ground) and the horizontally resolved force applied originally by the golf club. The two forces add together and if the horizontal force is great enough (i.e. you hit it hard enough) then it will stay in the air, but only unil the vertical force of gravity takes over and makes it fall back to earth.

Hopefully into the hole. Hope that's a hole-in-one answer for you! (ooh the bad puns just keep coming)

Answer 9

GPE=gravitational potential energy=energy which is released as an object falls, due to gravity KE=kinetic energy= energy an object possesses as it moves
when you hit it, you give it kinetic energy. unless something then affects the golf ball, the enrgy will not reduce, and speed remains constant. (as it goes higher, it also acquires GPE, and as it falls it loses GPE and gains KE, but for simplicity i'll ignore that)
as it flies through the air, collisions with air particles act as a force acting in the oppposite direction to the energy from when you hit it. if you subtract one from the other, you have the resultant force, which is the new KE, which is lower, so the golf ball goes slower. Of course, when it hits the ground it loses loads and loads, due to the ground being a bit more robust and able to reisst it than a random gas particle.

Answer 10

What keeps a Golf moving???

A Volkswagen Golf???

Anyway - sensible answer time, the kinetic energy from the golf club swing is trainsferred to the golf ball when it is struck. This energy provides the movement. The ball is constantly slowing down due to the other forces acting on it.