# Homework Help: Average speed and instantaneous, displacement and distance, speed and velocity

1. Oct 20, 2008

### xoxmiu

1. The problem statement, all variables and given/known data
What is the definition of average speed? How is average speed different from instantaneous speed? Explain.

2. Relevant equations
none

3. The attempt at a solution
Average speed is covering an equal amount of distance in an equal amount of time. Instantaneous speed, however, is speed at a specific time or given moment. While average speed is gradual over a period of time, instantaneous is just at one time.

1. What is the difference between distance and displacement? Speed and velocity?

2. Relevant equations
none

3. The attempt at a solution
Distance is a physical length, while displacement is from start to finish in one only one direction, and straight. Speed is the rate in which an object travel distance, whilst velocity the rate of change of position.

((I want to work on this; i am sketchy on this and my textbook is strangely very vague.))

2. Oct 21, 2008

### alphysicist

Hi xoxmiu,

I'm not sure what you mean, but this does not sound right to me.

This is true; the instantaneous value is the value at a specific time.

Average speed is calculated over an interval of time. So you might say the instantaneous speed at t=2 seconds is 5m/s, for example; on the other hand if you were talking about average speed you might say the average speed is 5m/s between t=2seconds and t=3seconds.

You determine the average speed by dividing the distance travelled (along the path) by the time interval that it took to travel that distance.