Let's analyze each situation to determine if the forces are balanced or unbalanced:
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Student Sitting at Desk:
- Balanced: The gravitational force pulling the student downwards is balanced by the normal force from the desk pushing upwards.
-
Rocket Launching:
- Unbalanced: During launch, the thrust produced by the rocket engines is greater than the gravitational force acting on the rocket, resulting in upward acceleration.
-
Building Collapsing:
- Unbalanced: The forces acting on the building (gravity, structural failure, etc.) result in an unbalanced state, leading to the collapse.
-
Car in Constant Speed on Straight Road:
- Balanced: If the car is moving at a constant speed in a straight line, the forces acting on it (such as friction and thrust from the engine) are balanced.
Based on this analysis:
- Student Sitting at Desk: Balanced
- Rocket Launching: Unbalanced
- Building Collapsing: Unbalanced
- Car in Constant Speed on Straight Road: Balanced