9. a block is sitting on a table. identify all the forces acting on it and explain why it doesnt move.\n10…
9. a block is sitting on a table. identify all the forces acting on it and explain why it doesnt move.\n10. a student says, \objects only have one force acting on them at a time.\ explain why this is incorrect, and give an example.\n11. a ball is kicked forward. describe how newtons first and third laws both apply in this situation.
Answer
9.
Brief Explanations:
The force of gravity pulls the block downwards towards the Earth. The table exerts a normal force upwards on the block. These two forces are equal in magnitude and opposite in direction, resulting in a net - force of zero. According to Newton's first law, an object at rest stays at rest when the net force acting on it is zero.
Answer:
The forces acting on the block are the force of gravity (downwards) and the normal force (upwards). It doesn't move because the net force on it is zero.
10.
Brief Explanations:
Objects can have multiple forces acting on them simultaneously. For example, a book on a table has the force of gravity pulling it down and the normal force from the table pushing it up. Also, if there is a gentle push on the book horizontally while it's on the table, there is the applied force and the frictional force opposing the applied force.
Answer:
The statement is incorrect because multiple forces can act on an object at once. Example: A book on a table has gravity and normal force acting on it.
11.
Brief Explanations:
Newton's first law: The ball was at rest before being kicked. When kicked, an unbalanced force is applied, and it moves forward. After the kick, it will continue to move forward in a straight - line at a constant speed if there were no other forces. But in reality, air resistance and friction from the ground act on it, eventually stopping it. Newton's third law: When the foot kicks the ball forward, the ball exerts an equal and opposite force on the foot.
Answer:
Newton's first law: An unbalanced force (the kick) changes the ball's state from rest to motion. After the kick, it would keep moving if not for other forces. Newton's third law: The ball exerts an equal and opposite force on the foot that kicks it.