v = u + at

v is the final velocity; u the initial velocity; a the acceleration and t the time taken.

If an object is thrown upwards the student has to decide if 'up' is the positive direction for velocity, in which case the acceleration is negative. Both are vector quantities. Or you can take acceleration as positive, which makes v negative. It is not usual to consider time as negative, but it is a scalar anyway. I have encountered problems where the solution was a negative t, meaning an event happened before the start time.

Bob

]]>OOoooh... I think I got it. speed = |velocity|

Wait... Does it imply that speed can be negative? O.o

]]>If you ran around in circles, your speed would be constant, but your velocity would be constantly changing. Your average velocity would be zero!

And so would your IQ.

Take that, track team.

]]>If you ran around in circles, your speed would be constant, but your velocity would be constantly changing. Your average velocity would be zero!

]]>and

http://en.wikipedia.org/wiki/speed

Havn't really had any of this yet, but you might find the answers there..

As far as I understand, velocity is a vector and speed is not..

Somebody please explain this madness.

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