Lesson 4-8 Rate-time- Lesson 4-8 Rate-time- Distance ProblemsDistance Problems

Lesson 4-8 Rate-time- Lesson 4-8 Rate-time- Distance ProblemsDistance Problems

D = rtD = rtD=distance r= speed t= timeD=distance r= speed t= time

• 1. At noon a private plane left Austin for Los Angeles, 2100 Km away, flying at 500 km/h. One hour later a jet left Los Angeles for Austin at 700 km/h. At what time did they pass each other?

Rate time Distance

Plane 500 t 500t

Jet 700 t - 1 700(t-1)

2100

• 500t + 700(t – 1)=2100• 500t + 700t – 700= 2100• +700=+700

• 1200t = 1400• 1200 1200

• t= 1h and 20 minute• At noon 12 + 1= 13 and 20 minute• Or 1:20 P.M

• At 8:00 A.M. the Smiths left a campground, driving at 48 mi/h. At 8:20 A.M the Garcias left the same campground and followed the same route, driving at 60 mi/h. At what time did they overtake the Smiths?

Rate Time Distance

Smiths 48 mi/h t 48t

Garcias 60 mi/h T – 1 3

60(t +1) 3

• 48 t = 60( t - 1/3)

• 48t = 60t - 20

• 12t = 20 t= 50 minute

• The Smiths overtake at 8:50