Answer:
The number of complete vibration or wave made in
one second is called frequency.
Answer:
Sorry, I don't understand this language, sorry dear
Answer:
So time taken by block to travel 0.5 m from rest will be 0.4853 sec
Explanation:
We have given mass of the block m = 6.7 kg
angle of inclination 
Distance traveled s = 0.5 m
Initial velocity u = 0 m/sec
Acceleration of the block 
From second equation of motion we know that 
So 

t = 0.4853 sec
So time taken by block to travel 0.5 m from rest will be 0.4853 sec