Speed, Distance, Time Calculations

The objective of this lesson is to be able to use the correct formulas to calculate speed, distance or time.

15 mins = 0•25 hour 30 mins = 0•5 hour 45 mins = 0•75 hour Reminder: How to change minutes into a decimal 15 mins = 0•25 hour So: 3 hours 15 mins = 3•25 hours 30 mins = 0•5 hour So: 7 hours 30 mins = 7•5 hours 45 mins = 0•75 hour So: 2 hours 45 mins = 2•75 hours

The 3 formulas for Speed, Time & Distance: Speed x Time Solving for Speed Solving for Time Solving for Distance D S T Remember them from this triangle:

Answer: His speed was 16 km / hour A windsurfer travelled 28 km in 1 hour 45 mins. Calculate his speed. Distance Time D S T Speed = 28 1•75 = 1 hour 45 mins = 16 km/h Answer: His speed was 16 km / hour

Let’s Try It! Speed = ? Distance = 25miles Time = 10minutes D S T

Let’s Try It! Speed = ? Distance = 15km Time = 8min. D S T

Let’s Try It! What is the speed of a car that traveled 150 miles in 2.5 hours? D S T

Your Turn! Speed = ? Distance = 39m Time = 20sec D S T

Your Turn! Speed = ? Distance = 235m Time = 120sec D S T

Your Turn! If a train travels 1500m in 250sec, how fast is the train traveling? D S T

Answer: He travelled 125 km A salesman travelled at an average speed of 50 km/h for 2 hours 30 mins. How far did he travel? D S T Distance = Speed x Time = 50 x 2•5 2 hour 30 mins = 125 km Answer: He travelled 125 km

D=180 m Let’s Try It! Speed = 12m/s Time = 15s Distance Traveled = ? D

Let’s Try It! Kiarra walks to school in the morning. It takes her 12 minutes to get to school when she walks at a speed of 3 miles per hour. How far does Kiarra live from school? D=0.6mi. D S T

D=40.8 mi. Your Turn! Speed = 12mi./hr. Time = 3.4 hrs Distance Traveled = ? D=40.8 mi. D S T

Your Turn! Jacob rides his bike to school. When he pedals at a speed of 4 meters per second, it takes him 9 minutes to get to school. How far does Jacob live from school? D=2160m D S T

Your Turn! When Chris takes the bus to school, it takes him 15 minutes to get to school. If the bus is traveling at a speed of 25 miles per hour, how far does Chris live from the school? D=6.25 mi. D S T

Answer: It took 9 hours 15 minutes A train travelled 555 miles at an average speed of 60 mph. How long did the journey take? D S T Distance Speed Time = 555 60 = = 9•25 hours = 9 hours 15 mins Answer: It took 9 hours 15 minutes

T=3.58hrs Let’s Try It! Distance = 251 miles Speed = 70 mi/hr Time = ?

Your Turn! Distance = 235 km Speed = 42km/hr Time = ? T=5.59hrs D S T

Your Turn! Beth is part of the school track team. She runs the 500 meter at a speed of 7 meters per second. What was her final time at the end of the race? T=71.42s D S T

Your Turn! Erica decides to walk home from school with her friends. If her house 1540 meters from school and she walks at a speed of 1.5 meters per second, how long will it take her to walk home? How many minutes would that be? T=1026.66s or T=17.11min D S T