Question

B. Fill in the blanks.
1. The fact that the time period of a pendulum remains the
same is used in a _______
clock.

2) Before crystals were used, the ______ used to measure
time in watches.

3. In a modern wrist watch, time is measured by the
vibrations of a ______ crystal.

4. The SI unit of speed is _______​

Answer 1

Answer:

1 m/ a

2 sand clock etc

speed

second