Can you answer this question about F = MA?

Question

OK, here is my question: F = MA, so if I strike a golf ball and my club is not accelerating. Why does the ball move? If acceleration is exactly zero then shouldn't the force equal zero also? I know it would be hard in reality to swing a golf club with exactly zero acceleration, but I am more interested in the concept, not how it necessarily applies to golf. And how does negative acceleration work in this situation?

Answer 1

Force is not a conserved quantity.

Thus you must appeal to either to conservation of energy or conservation of momentum.

Answer 2

Your ball does have an acceleration. While your club is moving at a constant velocity, your ball must start from rest and end up with a certain velocity toward the green. This is acceleration, a change in velocity.

It would be much easier to model this problem in terms of energy and conservation of energy. The kinetic energy of the ball is initially zero (at rest). After being struck by the club, the kinetic energy has some value. The club must have done work on the ball to change its kinetic energy and this work would imply that there is a force between the ball and the club. The club's acceleration cannot be zero in this situation unless some work is being done on the club, presumably by the player swinging the club.

Negative acceleration would work if you defined the direction you are hitting the ball as the negative direction.

Answer 3

Please remember that Newton's second law of Motion F=ma states that the Applied NET force is the rate of change of velovity. When the F is not zero, then acceleration a is not equal to zero.

From the F=ma formula, when a=0, the object may or may not be moving. a=0 simply mean that the object is moving with a constant velocity. Therefore the NET force may be zero by the forward force of motion of the club is NOT ZERO.

F=ma mean F1 - F2 = ma. F1 is the forward action of the club, F2 is the resistive force of air. F1-F2 is zero, hence awill be zero too but the ball will move forward.

In F=ma, the F is net net force and not the forward force alone. You must minus the forward force with the backward force, usually the resistive force.

Concept: When an object falls from the sky with a constant terminal velocity after, the acceleration is zero even if it falls with a gravitational acceleration of a=g=9.81 ms-2. Therefore, for a free fall object with terminal velocity, the Force is not zero but the NET force is zero.

In F=ma, when a=0. F=0 (NET force is zero)
The club has a forward force but is balanced with the frictional

Answer 4

The ball has to accelerate from zero. This may happen very quickly so you don't see it happen, it just appears to reach it's top speed instantly. It also changes shape as it's struck, so this is where some of the energy goes.

In terms of negative acceleration, acceleration is a vector (it has a directional compenent from velocity - speed in a given direction. Acceleration is rate of change of velocity, or metres per second squared.) so if Acceleration in a given direction is negative (usually meaning it is slowing down) then that means there is a force acting in the opposite direction of it's travel, so the force will be negative in that equation.

Answer 5

If you swing the club in a arc, it is acceleration.
But if the club moved at a constant velocity, it would still compress the golf ball, which would rapidly decompress, the force of which would accelerate it.

Answer 6

The club imparts a a force (F) on the ball with mass (M) and then the ball accelerates at rate A.

Answer 7

It's called the conservation of momentum & energy.

m1 v1 = m2 v2

m1 v1 are the mass and velocity of your golf club.
m2 v2 are the mass and velocity of your golf ball.

BTW technically the club is accelerating as you are performing motin in a circle - so although your velocity may be constant, you are accelerating.

Answer 8

who said the golf club is not accelarating???
when u swing the club doesnt it accelarate