At the subduction zone a very deep trench is formed in the ocean floor. Oceanic and oceanic plate convergence result in the formation of volcano chains. The crust that is pulled under or subducted melts to form magma. This magma rises to the top of the overriding oceanic plates and erupts on the ocean floor.
So the answer would be Volcano
Answer:
b. slow-moving streams.
Explanation:
In Fluid Mechanics, the Reynolds numbers indicates the existence of turbulence in fluid streams. Low Reynolds numbers are related with laminar flow. The Reynolds formula is:

The Reynolds number is directly proportional to fluid speed. Hence, slow-moving streams are a sound example of laminar flow. The correct answer is B.
Answer:
The tangential speed of the tack is 8.19 m/s.
Explanation:
The wheel rotates 3.37 times a second that means wheel complete 3.37 revolutions in a second. Therefore, the angular speed ω of the wheel is given as follows:

Use the relation of angular speed with tangential speed to find the tangential speed of the tack.
The tangential speed v of the tack is given by following expression
v = ω r
Here, r is the distance to the tack from axis of rotation.
Substitute 21.174 rad/s for ω, and 0.387 m for r in the above equation to solve for v.
v = 21.174 × 0.387
v = 8.19m/s
Thus, The tangential speed of the tack is 8.19 m/s.