A dog runs down his driveway with an initial speed of 5.0 m/s for 8 seconds then uniformly increases his speed to 10 m/s in 5 seconds, how long is the driveway? SHOW WORK

to find the displacement, or delta x (change in position) on a velocity graph, you can find the area under the line on the graph: between 1 and 8 seconds, the dog was going at 5m/s, so 5m/s x 8s=40m, for the second part, you have to find the area of both a triangle and a rectangle, so the rectangle would be 5m/s x 5s=25m and the area under the triangle would be (5m/s x 5s)/2=25m/2=12.5m -you divide by 2 because it's a triangle

-afterwards, you would add the area of the 2 sections together, so 40m+25m+12.5m=77.5m

Explanation:

no. dot product   =0 when vecs at right angles