The device measures G forces as the ball accelerates and deaccelerates.
Yes. When the ball is going up, it is getting slower and slower. It’s decelerating because of the only force acting on it, gravity, 1G. The reason it decelerates is that the force is acting in the
opposite direction to it’s movement.
A moment later, when the ball has slowed to say half it’s start speed, has gravity changed? It the force now 0.5G or 2G? Of course not.
When the ball stops moving at the top of it’s trajectory, it is neither decelerating nor accelerating, it is stationary. But the force acting on it has not changed, it’s still 1G.
During it’s descent it is accelerating, getting faster and faster towards the ground, but the force has still not changed, 1G. The reason it accelerates is that the force is acting in the
same direction to it’s movement.
The ball has experienced changes in speed and changes in direction, but the force has not changed. It has been a constant 1G the whole time.
But when the ball comes to rest on the ground, or in your hand, THEN the forces acting on it HAVE changed. It now has two equal and opposite forces acting together that exactly cancel each other out so that the ball does not move. The force of gravity and the force applied by your hand. If one of these forces was slightly stronger than the other, the ball would begin to accelerate. For example during the throw. You apply a force (upwards) that is greater than gravity and so the ball accelerates upwards. Until the ball leaves the hand, there are two forces acting on it, but once it has left the hand, it’s only gravity again.
If what your putting forward is correct we would not feel G forces when a car accelerates or brakes.
No. The forward and backward push you experience in a car are nothing to do with gravity. Any speed change of the car must be the result of an applied force. In this case the engine or breaks. But your body is not connected to either. You are connected only by your back on the seat and your hands on the wheel. When the car accelerates or decelerates, the forces pass through these points of contact to accelerate or decelerate you.
Simple Newtonian laws of motion. A body at rest tends to remain at rest unless an external force is applied. A body in motion tends to remain in motion unless an external force is applied.
In the case of the car, the force is applied by the engine to the wheels, from the wheels to the car chassis, from the chassis to the seat, then from the seat to your back. Each one of these steps takes time and causes physical stress at the points of contact (bending/heating/crushing etc.). In the case of the thrown ball, the only applied force is gravity. It acts equally and simultaneously on every part of the ball inside and out. Until it is caught.