Answer:
(a) Three third law pairs of forces can be identified based on Newton's third law of motion, which states that for every action, there is an equal and opposite reaction. In this case, the third law pairs of forces can be identified as:
- Force A (upward) and Force D (downward)
- Force E (downward) and Force B (upward)
- Force C (upward) and Force F (downward)
These pairs of forces act on different objects but have equal magnitudes and opposite directions, satisfying the requirements of Newton's third law.
(b) Three first law pairs of forces can be identified based on Newton's first law of motion, which states that an object at rest will remain at rest unless acted upon by an external force. In this scenario, since the cart is stationary, it is not experiencing any net external force. Thus, the first law pairs of forces can be identified as:
- Force A (upward) and Force D (downward)
- Force E (downward) and Force B (upward)
- Force C (upward) and Force F (downward)
These pairs of forces are balanced, resulting in no net force acting on the cart and keeping it stationary.
(c) Four random pairs of forces can be identified as:
- Force A (upward) and Force E (downward)
- Force D (downward) and Force F (downward)
- Force B (upward) and Force C (upward)
- Force S (random direction) and Force H (random direction)
These pairs of forces are not necessarily related by Newton's laws of motion but are mentioned as random pairs in the given scenario.