# What does the V vs T graph represent?

## What does the V vs T graph represent?

A velocity-time graph shows changes in velocity of a moving object over time. The slope of a velocity-time graph represents acceleration of the moving object.

### What is the difference between a distance time graph and a velocity-time graph?

Distance time graph tells us how much distance you have traveled while the velocity-time graph tells you your acceleration.

**What is the physical significance of the slope of your graph of V vs T?**

It was learned earlier in Lesson 4 that the slope of the line on a velocity versus time graph is equal to the acceleration of the object. If the object is moving with an acceleration of +4 m/s/s (i.e., changing its velocity by 4 m/s per second), then the slope of the line will be +4 m/s/s.

**What does the slope of velocity versus time graph represent and what is its value?**

The slope of a velocity graph represents the acceleration of the object. So, the value of the slope at a particular time represents the acceleration of the object at that instant.

## When a velocity vs time graph is slowed downwards is the object still moving forward?

The period from 15 min to 30 min for example, shows the object slowing down, but still moving forward. When this line crosses the t-axis, the object has (momentarily) stopped, and is in the process of changing direction. Negative velocity must mean movement in the opposite direction.

### How can you quickly tell by looking at a distance vs time graph whether or not the object has constant or changing speed?

On a distance-time graph, there are no line sloping downwards. A moving object is always ‘increasing’ its total length moved with time. ‘Curved lines’ on a distance time graph indicate that the speed is changing. The object is either getting faster = ‘accelerating’ or slowing down = ‘decelerating’.

**What is the relationship between velocity and time?**

Velocity is directly proportional to time when acceleration is constant (v ∝ t). Displacement is proportional to time squared when acceleration is constant (∆s ∝ t2).