Solving equations in everyday situations. (1)

Today I'm going to be talking about solving physics-type equations based on real life situations - this one being a dog out for a walk. To solve this puzzle a knowledge of only two equationss are needed: Velocity and Kinetic Energy.

We are given three pieces of information in this problem:

- The weight of the dog: 20kg
-The distance walked: 1km
-and the time taken: 20 minutes.

Firstly we need to calculate the dogs velocity using this equation:

This means: velocity = change in distance/ time taken.

The initial distance was 0 as the dog started from nothing and the final distance was 1km and the time taken was 20 minutes or 1200 seconds so the dogs velocity is: 0.83 m/s.

Now that we have the velocity we can calculate the dogs kinetic energy using this equation:

We know the mass which is 20kg and the velocity which is 0.83 m/s. So we need to do 1/2(20(0.83*0.83)) which is 6.89J of Kinetic energy.

So there a seemingly daunting problem solved with the use of only two equations.

This is only a short post but since I'm doing another 'mini series' on equations these posts won't be too long - thanks for reading, Chris.