World of Wall » Science 10

Science of Motion 5 – calculating using acceleration

rjw — Sun, 11 Dec 2011 14:22:49 +0000

Knowing some basic concepts about displacement, time, velocity and acceleration can let us do some pretty powerful calculations to describe an object’s motion, like how long it takes for an airplane to accelerate to takeoff on an aircraft carrier:

Science of Motion 4 – acceleration

rjw — Fri, 09 Dec 2011 22:22:33 +0000

Not all motion is at a constant velocity. Objects will speed up or slow down as forces act on them. A velocity can change slowly (think of a ball rolling down a long, low ramp) or quickly (like a Corvette accelerating down the road. The rate of change of velocity (how slowly or quickly it changes) is the object’s acceleration. The ball rolling down the low ramp has a much lower acceleration than the Corvette.

Here’s an example of calculating the rate of change of velocity of a car as it accelerates to 60 miles per hour:

Converting units tutorial

rjw — Wed, 30 Nov 2011 18:20:58 +0000

Unit conversions will, as we have seen, come up frequently in studying motion such as when we are converting yards per second into kilometres per hour. Unit conversions are also an import part of calculations in many other areas of science. Here’s a quick explanation/example of unit conversions:

Science of Motion 3 – solving for time and distance

rjw — Mon, 28 Nov 2011 18:27:17 +0000

Since we know about the relationship between velocity, displacement and time, we can use that formula to find velocity or time or displacement as long as we know the two other variables.

First – finding the time if you know the velocity and the displacement:

And how do find the displacement if you know the velocity and the time:

So, given this information, here’s my question for you. If I leave North Battleford at 2:00 for a 3:00 dentist appointment in Saskatoon (which is about 140 km away) and drive at an average speed of 110 km/hour (I’ll drive very fast in Saskatoon), how long will it take me to get to Saskatoon? How late will I be for my appointment? (Give me the answer to either or both of these questions in class, including showing your calculations, and you will be rewarded, probably with leftover Halloween treats).

Science of Motion 2 – Calculating Average Velocity or Speed

rjw — Mon, 28 Nov 2011 16:26:32 +0000

You’ll use this type of calculation not only in the motion labs, but also in some problems that you’ll be asked to solve in future classes. It’s also good to know if you want to avoid a speeding ticket.

Science of Motion 1 – Scalars and Vectors

rjw — Mon, 21 Nov 2011 15:24:40 +0000

Measurements in science can be classified into two types – scalars and vectors. The difference is explained in the following video:

Can you think of other measurements that are scalars? What about measurements that are vectors?