**The smallest to the biggest thing in the universe. **

This video shows the various prefixes used to denote very small or big numbers.

Is Usain Bolt faster than a typical car on the road with a constant speed of 60 km/h?

Calculate the average speed of Usain Bolt for the 100 m world record of 9.58 s in m/s. Then convert it to km/h to do a comparison.

Wanna watch his 200 m race?

**How to use a vernier caliper?**

The precision of vernier caliper is 0.01 cm (0.001 m).

**How to use a micrometer screw gauge?**

The precision of the micrometer is 0.01 mm

**Factors that affect the period of the pendulum bob
**Only length and gravitational field strength (g) affect the period.

*– Length of pendulum increases, period (T) is longer*

*– Gravitational field strength (g) decreases, period (T) is longer (i.e. on the moon)*Mass of pendulum bob and angle of release (5 to 10 degree) will not affect the period (T).