Question

1. sandra pushed a wooden block and it slid across the floor. the wooden block gradually slowed down and stopped after moving 10 meters.

why did the block stop moving?
a the floor exerted a force that is opposite to the direction of the blocks motion.
b the block ran out of force.
c the floor absorbs force from the block.
d all objects stop moving because their natural state is to be still.

Explanation:

When an object is in motion on a surface, the surface exerts a frictional force. Frictional force acts in the opposite direction to the motion of the object. In this case, the floor (surface) exerts a force (frictional force) on the wooden block which is opposite to the block's motion. This frictional force causes the block to slow down and eventually stop.

• Option b: Objects don't "run out of force". Force is an interaction. Once the pushing force is removed, the main force acting is friction.
• Option c: The floor doesn't "absorb" force in the sense described here. It exerts a reaction (friction) force.
• Option d: Objects don't have a "natural state to be still" in the context of Newtonian mechanics. An object in motion will stay in motion unless acted on by an external force (like friction here).

Answer:

A. The floor exerted a force that is opposite to the direction of the block's motion.