A mirror is opaque you can not see through it but you can see a reflection within it
Answer:
The fundamental frequency of can is 2.7 kHz.
Explanation:
Given that,
A typical length for the auditory canal in an adult is about 3.1 cm, l = 3.1 cm
The speed of sound is, v = 336 m/s
We need to find the fundamental frequency of the canal. For a tube open at only one end, the fundamental frequency is given by :
So, the fundamental frequency of can is 2.7 kHz. Hence, this is the required solution.
Answer:
a) 70 N, b) b. Each initially applied a force bigger than static friction to get the box moving and accelerating, then when the desired final speed was achieved they reduced the force to make the net force zero.
Explanation:
a) A constant speed means that magnitude of friction force is equal to the magnitude of the external force. The friction force is directly proportional to the normal force, which is equal to the weight of the box. Therefore, the magnitude of the force is 70 N.
b) Alice used initially a greater force to accelerate the box up to needed speed and later reduced the external force to keep speed constant. The right choice is option b.
<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