Answer:
Average speed is 60 km/hr whereas average velocity is 0 km/ hr.
Explanation:
The average speed of the boat is 60 km/ hr while on the other hand, the average velocity of the boat is 0 km/ hr because average speed is the total distance covered by the boat in total time and average velocity is the displacement covered by the boat in total time. The total distance covered by the boat is 60 km and the total time is 60 minutes which is equals to one hour so the answer is 60 km/hr whereas the displacement is the shortest distance between initial and final position which is 0 in this case so 0 divided by 60 minutes or one hour is also 0.
Answer:
Explanation:
In order to answer this problem you have to know the depth of the column, we say R, this information is important because allows you to compute some harmonic of the tube. With this information you can compute the depth of the colum of air, by taking tino account that the new depth is R-L.
To find the fundamental mode you use:

n: mode of the sound
vs: sound speed
L: length of the column of air in the tube.
A) The fundamental mode id obtained for n=1:

B) For the 3rd harmonic you have:

C) For the 2nd harmonic:

The car will speed up because if the air resistance and friction forces are reacting in the direction opposite to the Applied force, The Net force will still be in the direction of the car's motion and since F=ma a will cause your velocity to increase
the answer would be d. volcanic but im not 100% sure