Answer:
Hits per second=199 hit/s
Explanation:
#Given the angular velocity,
, radius of the record
and the distance between any two successive bumps on the groove as
.
The linear speed of the record in meters per second is:

#From
above, if the bumps are uniformly separated by 1m, then the rate at which they hit the stylus is:

Hence the bumps hit the stylus at around 199hit/s
That would be a the first law of newton's laws of motion because it stops from an external force
<u>Answer</u>:
The stream flowing at a speed of 
<u>Explanation</u>:
Given:
Distance = 2km (both in upstream and downstream)
The speed in still water be x km/hr.
The speed in upstream = 4-x
Speed in downstream = 4+x
Solution:
We know that, Speed = distance/time
So, Time = distance/speed
Therefore,




By cancelling 2 on both sides,




Result:
Thus the speed of the stream is 