Final answer:
The information provided relates to the application of physics concepts in rugby, such as momentum and force, rather than the actual number of players involved in a touch rugby scrum.
Step-by-step explanation:
The number of players in a scrum in touch rugby varies according to the specific game rules, but is not addressed in the provided information. Instead, the provided information discusses the physics concepts related to rugby, such as momentum and the forces exerted by and on rugby players.
For example, when considering the resultant force on a rugby player, we could use the graphical head-to-tail method to sum the forces acting on the player: two teammates pushing forward with forces of 60 N and 90 N, and two opponents pushing backward with forces of 100 N and 65 N. The net force acting on the player can be calculated by subtracting the sum of the opposing forces from the sum of the forward forces.
In another scenario involving forces, a rugby player is being pushed backward with a force of 800 N. By knowing the mass of the player (90.0 kg) and the acceleration (1.20 m/s²), we can calculate the force of friction between the player's feet and the ground. Additionally, we could determine the force the opposing player exerts on the ground if we know his mass, which includes his equipment (110 kg).