A fairground sling-shot is shown below - Leaving Cert Physics - Question 6 - 2017

The form of energy that the pod has due to its motion is kinetic energy. It is calculated using the formula: $KE = \frac{1}{2} mv^2$, where $m$ is the mass and $v$ is the velocity of the pod.

At its highest point, the pod possesses potential energy. This energy can be calculated using the formula: $PE = mgh$, where $m$ is the mass, $g$ is the acceleration due to gravity, and $h$ is the height.

The occupants experience apparent weightlessness at the pod's highest point because they are in free fall. At this point, the only force acting on them is gravity, which creates a sensation of weightlessness as they do not exert any force against the pod.

The potential energy (PE) stored in the springs can be calculated as follows:

$PE = mgh = 400 imes 9.8 imes 50 = 196000 ext{ J}$

The forces acting on the pod at the moment of release include:

1. Weight (W) acting downwards, calculated as $W = mg$.
2. Spring force (F) acting upwards (restoring force from the springs). The net force on the pod at this moment is determined by the difference between the upward spring force and the weight.

The momentum (p) of the pod can be calculated using:

$p = mv = 400 ext{ kg} \times 8 ext{ m/s} = 3200 ext{ kg m/s}$

One energy loss that might prevent the pod from reaching its maximum height is friction or air resistance, which opposes the motion and dissipates energy as heat.