Relative Motion in Physics

Study Notes

The distance between two bodies is the sum of their displacements from a common origin point.
When two objects move towards each other, their displacements are calculated from a shared reference point.

An object overtakes another when they have the same displacement from a certain point.
If objects start from the same point, it's easy to determine when they will catch up.
If one object starts ahead of the other, the difference in their initial displacements must be added to the equation.
If objects start at the same point but at different times, the time difference is added to the equation.

For one object to fully pass another, it must cover a distance equal to the total length of both objects.
The difference in displacements between the two objects must be equal to this distance.

When an object is in free fall, only gravity acts on it, causing it to accelerate towards the ground at 9.8 m/s² near the Earth's surface.
Steps to solve a free fall problem:
- Identify the equation of motion with only one unknown variable.
- Substitute known values, including acceleration (a = -9.8 m/s²).
- Ensure consistent sign convention for vectors pointing up and down.
- Solve for the unknown variable.
- For maximum height, the object's speed is 0.

The distance between two bodies is the sum of their displacements from a common origin point.
When two objects move towards each other, their displacements are calculated from a shared reference point.

An object overtakes another when they have the same displacement from a certain point.
If objects start from the same point, it's easy to determine when they will catch up.
If one object starts ahead of the other, the difference in their initial displacements must be added to the equation.
If objects start at the same point but at different times, the time difference is added to the equation.

For one object to fully pass another, it must cover a distance equal to the total length of both objects.
The difference in displacements between the two objects must be equal to this distance.

When an object is in free fall, only gravity acts on it, causing it to accelerate towards the ground at 9.8 m/s² near the Earth's surface.
Steps to solve a free fall problem:
- Identify the equation of motion with only one unknown variable.
- Substitute known values, including acceleration (a = -9.8 m/s²).
- Ensure consistent sign convention for vectors pointing up and down.
- Solve for the unknown variable.
- For maximum height, the object's speed is 0.