Steady or changing speed
Uniform and non-uniform linear motion.
A train between two stations
A train leaves station A slowly, speeds up, runs steadily, slows down and stops at station D. The track is a straight line.
Is its speed the same all the way?
What this lesson covers
The idea
Motion along a straight line is linear motion; an object moving along a straight line with constant speed is in uniform linear motion, and one whose speed keeps changing is in non-uniform linear motion.
A train between two stations
A train leaves station A slowly, speeds up, runs steadily, slows down and stops at station D. The track is a straight line.
Is its speed the same all the way?
- No, it changes in some parts and stays constant in one part
- Yes, it is the same all the way
- It does not move at all
Run the train
Press Run the train. Watch the speedometer and the green part of the track.
Uniform and non-uniform
From B to C the speed stayed constant: uniform. From A to B and from C to D the speed kept changing: non-uniform. All along a straight line.
Motion along a straight line is linear motion; an object moving along a straight line with constant speed is in uniform linear motion, and one whose speed keeps changing is in non-uniform linear motion.
- Part of the journey | Speed | Kind of motion
- A to B | Keeps changing | Non-uniform
- B to C | Constant | Uniform
- C to D | Keeps changing | Non-uniform
Notes
Motion along a straight line is linear motion; an object moving along a straight line with constant speed is in uniform linear motion, and one whose speed keeps changing is in non-uniform linear motion.
Check yourself
Motion along a straight line is called …
A train moves along a straight line at a constant speed. This is …
A train between A and B keeps changing its speed. This is …
Which part of the journey of the train was uniform linear motion?
- circular motion. Circular motion is along a circle, not a straight line.
- random motion. Linear motion is the name for motion along a straight line.
- linear motion — correct. Yes!
- uniform linear motion — correct. Yes!
- non-uniform linear motion. Non-uniform means the speed keeps changing.
- no motion. The train is moving, at a constant speed.
- uniform linear motion. Uniform means constant speed.
- non-uniform linear motion — correct. Yes!
- circular motion. The track is a straight line, so it is linear motion.
- A to B, where the speed kept changing. Changing speed is non-uniform.
- C to D, where the speed kept changing. Changing speed is non-uniform.
- B to C, where the speed was constant — correct. Yes!