Which Equation Do I Use?
If you want to find distance, which formula should you use?
distance=speed×time
What is the SI unit of distance?
meter (m)
A turtle walks 4 m in 2 s. What is its speed?
4÷2=2 m/s
A dog runs at 2 m/s for 3 s. How far does it go?
6 m
Which is faster: 3 m/s or 5 m/s?
5 m/s
If you want to find speed, which formula should you use?
speed=distance/time
What is the SI unit of speed?
meters per second (m/s)
A cyclist travels 10 km in 2 hours. What is their speed?
10÷2=5 km/h
A train moves at 50 km/h for 2 hours. How far does it travel?
100 km
A student says “my time was 20 meters.” What mistake did they make?
They used units of distance instead of time.
You know the speed and the distance. Which equation finds the time?
time=distance/speed
A student writes a speed as “12 m”. What’s wrong?
Speed needs units of distance / time (e.g., m/s)
A robot moves at 3 m/s for 5 seconds. How far does it travel?
3×5=15 m
A student walks 1 m/s for 10 seconds. How far do they walk?
10 m
A fish swims 12 m in 3 s. A crab crawls 8 m in 2 s. Who is faster?
Fish = 12/3 = 4 m/s
Crab = 8/2 = 4 m/s
How do you use the DST triangle?
You cover what you want to find.
What does the unit km stand for?
distance
A runner travels 100 m at a speed of 5 m/s. How long does it take?
100÷5=20 s
A rocket drone flies 4 m/s for 8 seconds. How far does it travel?
32 m
You measure speed in km. What unit is missing?
A time unit (km/h)
True or False: If you know any two of the variables (distance, speed, time), you can always calculate the third.
True
15m/s is a measurement of?
speed
A car drives 60 km at 30 km/h. How long does the trip take?
60÷30=2 hours
A robot car moves 20 km at a speed of 5 km/h. How long is it moving?
4 hours
A student calculates a speed of “4 s/m.” What went wrong?
They flipped the units (should be m/s)