Solution:
We have,
Power [P] = 25000 Watt
Mass [m] = 6000 kg
Height [h] = 20 metres
Time [t] = ?
Now,
P = W/t = F x d/t = mxgx h/t
Or, 25000 = 6000 x 10 x 20/25000 [.......g = 10
m/s^2]
Or, t = 6000 x 10 x 20/25000
Or, t = 1200/25
Therefore, t = 48 second
Hence, the required time for the crane to lift the load is 48 seconds.
The answers to this question is the 4th one
Answer:
The situation where a seafloor plate slides under a continental plate during subduction is best described by convergent plate boundary.
Explanation:
The earth’s crust is broken down into tectonic plates that can move independently. They can interact in three different ways: converge (move toward one another), diverge (move away from one another) or transform (slide past one another). The three kinds of plate margins (boundaries where plates meet) are oceanic-oceanic, continental-continental, and continental-oceanic.
The regions where the plates are moving towards one another are known as convergent plate boundaries. During the convergence of continental and oceanic plates, the more-dense oceanic plate sinks below the less-dense continental plate and the oceanic plate is forced down further into the mantle. This is known as subduction. When the plate enters the mantle, the inside pressure breaks the rock. The broken rocks begins to melt from the heat due to the friction and as a result magma is formed. This magma rises toward the surface by breaking through the crust and forms a chain of volcanoes known as a volcanic arc such as the Cascade Mountains of North America and the Andes Mountains of South America.
During the convergence of two oceanic plates, one of the plates sinks underneath the other and forms an ocean trench (deep depression). The plate that sinks further down into the mantle starts to melt and as a result magma rises toward the surface and forms a chain of volcanic islands behind the ocean trench.
During the convergence of two continental plates, they buckle and compress to form complex mountains ranges of great height such as the Himalayas.
