Read the following case and answer the question given below:
A toy car was placed on a smooth floor by a student and pushed lightly. It moved slowly before stopping after a short distance. The student then applied a stronger push, making the car move faster and cover a greater distance. When the moving car collided with a wooden block, its speed decreased and its direction changed slightly. Friction acted opposite to the car’s motion throughout the experiment.
1. What caused the toy car to start moving?
2. Why did the toy car move faster after the harder push?
3. Which force acted opposite to the motion of the toy car?
4. Why did the toy car finally stop moving?
5. What happened to the velocity of the toy car when it hit the wooden block?