Distance-Time Graphs and Motion Basics
Distance-time graphs are like visual stories of how objects move. The gradient (steepness) of the line tells you the speed - a steeper line means the object is moving faster, whilst a horizontal line means it's stopped.
When you see curves on the graph, that's acceleration in action. A steepening curve shows the object is speeding up (increasing gradient), while a levelling off curve means it's slowing down (decreasing gradient). Think of it like a car accelerating away from traffic lights, then easing off as it approaches the speed limit.
Acceleration is simply how quickly something speeds up or slows down at a constant rate. The formula is a = Δv/t (change in velocity divided by time). Remember, deceleration is just negative acceleration - it's not a completely different concept, just acceleration in the opposite direction.
Top Tip: You don't need to memorise the basic distance, speed, time equations - they're given in your exam! Focus on understanding how to use them instead.
The key difference between scalar and vector quantities is direction. Speed and distance are scalars (no direction), whilst velocity and displacement are vectors (include direction). It's like the difference between saying "I'm going 30 mph" versus "I'm going 30 mph north".