Question 66475
A private airplane leaves an airport and flies due south at 192 km/h.  Two hours later a jet leaves the same airport and flies due south at 960 km/h.  When will the jet overtake the plane?
THANK YOU!

distance (d)=rate (r)  times   Time (t)
d=rt


Let t=time it takes for the jet to catch the private plane

Now we are told that when the jet leaves, the private plane has already been flying for two hours. Therefore, the private plane has already traveled a distance of  (192km/h)(2h)=384 km

(960)(t)= distance travelled by the jet when the private plane is overtaken

384+(192)(t)=distance travelled by the private plane with it is overtaken

When these two distances are equal, the private plane will be overtaken.  So our equation to solve is:

960t=384+192t  subtract 192t from both sides: 
960t-192t=384
768t=384
t=.5h=.5(60)m

t=30 minutes after the jet takes off, it will overtake the private plane

ck

(960)(.5)=384+192(.5)

480=384+96
480=480


Hope this helps----ptaylor