# SPEED AND VELOCITY

Speed - who cares? We live in a Universe where **everything** is moving relative to each other. The Earth rotates as it orbits a star that in turn is orbiting around a black hole at the centre of a galaxy. Our galaxy itself is accelerating towards the Andromeda galaxy due to gravitational attraction whilst the very space that makes up the Universe expands in all directions. Light and other electromagnetic radiation streams throughout that expanding universe at the fastest speed possible, around 300,000,000 m/s, and nothing can match that. Meanwhile, we insignificant little creatures move across the surface of that planet at tiny speeds, outpacing snails but unable to outrun most predators, which is why we invented cars, weapons and built fires, er.... but I digress..... in simple terms,** Speed** tells us how **far** an object moves in a certain** unit of time**. It has many** units** including kilometres per hour and miles per hour. In physics, we use the S.I. unit of metres per second (m/s). Speed is a **scalar quantity. **It has** magnitude** only**. Velocity **is the **vector **equivalent of speed**. **It needs to be stated with a **direction **too**. ** But how do we **measure and calculate** the** speed or the velocity** of and object? Here is one of our little retro science geek videos with some more information.....

### SPEED AND VELOCITY - KEY FACTS

Apparently, the **human brain** remembers facts best if you group them into** odd **numbers. Best of all is groups of **FIVE**! Let's see if the actually works with our super **"fivey facts animated GIF"** below.... how many can you remember? Use this cunning revision technique by making other collections of **fivey facts** on different topics!

## SPEED CALCULATIONS

Using the speed equation is essential not just for pesky science assessments but also in real life. It can be used to estimate time of arrival during car journeys or how fast you need to drive to get to places in a certain time. It can be used ....er....actually .. that's it, unless you become a motor racing engineer or vehiclle designer or particle accelerator physicist, atronomer or atheletics sport coach scientist......Anyway, here is how to go about speed calculations. Try the quiz once you are done and confident. Note the equation given shows velocity = displacement/ time................ Lazy physicists use these symbols all the time when calculate speed = distance/time too. Don't be phased.

## DISTANCE - TIME GRAPHS

Distance -time graphs? Who cares? I don't. What are these one dimensional anachronisms for? I googled it and struggled to find anything convincing. Oh well. The truth is... people love to ask you questions about them in Maths and Physics exams and, to be fair, they are really for useful for build up general graph skills like calculating gradients, extracting data and interpreting the shapes of graphs..... And they are quite an easy way to pick up marks in assessments once you have grasped them....Enjoy!

### NOW IT'S YOUR TURN!

After studying the animation above - can you describe what is going on in each section of the graph below.... hover over the line to find the answer. Enjoy!

## DISTANCE - TIME GRAPH VIDEO

There are often things in life you regret. This video is one of them. Filmed at the dawn of video editing. This retro science videos pushes the boundaries of sanity and shatter's them. Distance time graphs explained by people who should know better. The "funny bunny" is the real star of the show and went on to a successful career. Apologies. Weird.... but strangely educational...

### Speed, Velocity and Distance Time Graph Quiz!

Come on quiz fans! Show us what you are made of. Can you get full marks on all the topics covered on this page.... can you go the "distance"? Get it? "distance"? #illgetmycoat