Spongebob and Patrick are running away from the Krusty Krab. Spongebob runs east at 4 feet per second while Patrick runs west at 2 feet per second. How long will it take them to be 192 feet apart?

1 Answer
Sep 24, 2015

For the time being, we can ignore the signs of their velocities, but rather add their speeds. So the total speed we can say is

#4+2=6(ft)/s#

We are trying to find the time, so we can set up a proportion:

#(6ft)/s=(192ft)/(xs)#

which gives us #x = 32s#

We can check by multiplying the time by their individual velocities:
Spongebob: #32cancel(s) * 4(ft)/cancel(s)=128 ft# to the right
Patrick: #32cancel(s) * 2(ft)/cancel(s)=64 ft# to the left
When you add these two together you find #192ft#.