Final answer:
Restraint in mechanical joints to resist thrust cannot be oversimplified to true or false without proper context. Several fundamental physics principles surrounding forces are highlighted, indicating which statements are true or false based on the laws of motion and force.
Step-by-step explanation:
The concept of restrained push or restrained mechanical joints being used to resist thrust forces is more complex than a simple true or false statement. In the engineering context, particularly when dealing with structures or piping systems, a restrained push on joints or mechanical joints can indeed be designed to resist thrust forces that occur due to internal pressures or thermal expansion. These are critical in maintaining the integrity of a system under various loads. However, without context, the question is too vague to be definitively answered as true or false.
As for the other true or false statements related to physics and force:
An external force is required to set a stationary object in motion in outer space (True)
When two unequal forces act on a body, it will not move in the direction of the weaker force (True)
If a rope in a tug-of-war snaps, the forces were equal at the point of snapping, as the rope would not have snapped if one force greatly exceeded the other (Not stated but implied)
Normal reaction is an opposing force to gravity and does not act in the direction of gravity (False)
A boy pushing a box up a ramp does not necessarily exert a force of exactly 100 N based solely on the height and length of the ramp. The actual force depends on the friction and slope of the ramp (False)
Kinetic friction is generally less than static friction, requiring more force to initiate movement than to maintain it (True)
An external force refers to any force that originates outside the system considered and has an effect on an object within the system (True)
Newton's third law applies to all forces, including external ones, in a system (True)