SI units, prefixes and converting with unit analysis

Answer Key - Grade 10 Science Worksheet

Circle the best answer, or write your answer on the line.

1. 1.

   A train moves at 90 km/h. Using unit analysis, what is that speed in m/s, Ari?

   25 m/s
2. 2.

   A bus moves at 54 km/h. Using unit analysis, what is that speed in m/s, Bo?

   15 m/s
3. 3.

   A train moves at 108 km/h. Using unit analysis, what is that speed in m/s, Esme?

   30 m/s

4. Read this first

   Measurement card with a chain of conversion factors

   72 km/h × (1000 m ÷ 1 km) × (1 h ÷ 3600 s) = 20 m/s. The km and the h cancel, leaving m/s.

5. 4.

   On the chain card, what cancels the km in 72 km/h, Jun?

   • The km in 1000 m ÷ 1 km
   • The h in 1 h ÷ 3600 s
   • The m in 20 m/s
6. 5.

   On the chain card, which units are left after canceling, Luz?

   • m/s
   • km·s
   • km/h
7. 6.

   Which factor turns 750 mL of milk into liters, Noah?

   • 1 L ÷ 1000 mL
   • 1 L ÷ 100 mL
   • 1000 mL ÷ 1 L
8. 7.

   Which chain turns 2 hours into seconds, Pia?

   • 2 h × (1 h ÷ 60 min) × (60 s ÷ 1 min)
   • 2 h × (60 min ÷ 1 h) × (60 s ÷ 1 min)
   • 2 h × (60 s ÷ 1 h)
9. 8.

   How is 5 μm written in meters, Ren?

   • 5 × 10⁶ m
   • 5 × 10⁻³ m
   • 5 × 10⁻⁶ m
10. 9.

    Red light has a wavelength of 650 nm. What is that in meters, Tala?

    • 6.5 × 10⁻⁴ m
    • 6.5 × 10⁻⁷ m
    • 6.5 × 10⁻⁹ m
11. 10.

    How many meters are in 3.2 km, Zee?

    • 0.0032 m
    • 3200 m
    • 320 m