Answer:
The importance of international bureau of weights and measures are;
1. to bring unification of measurement system.
2. to establish and preserve fundamental international prototypes.
3. to verify national standards, etc.
Answer:
Time period, 
Explanation:
We have,
The frequency of an FM radio station is 89.3 MHz.
It is required to find the period of the wave.
The reciprocal of frequency is called time period of a wave. It can be given by :

So, the period of the wave is
.
Answer:
An object which moves in the positive direction has a positive velocity. If the object is slowing down then its acceleration vector is directed in the opposite direction as its motion (in this case, a negative acceleration).
Explanation:
The drop in physical activity is partly due to inaction during leisure time and sedentary behaviour on the job and at home. Likewise, an increase in the use of "passive" modes of transportation also contributes to insufficient physical activity.