The correct answer is:
c. convection.
The heating of magma and the continuous cycle of evolution of the magma creating a convection current is the reason for the evolution of Earths tectonic plates.
Explanation:
Tectonic plates are ready to move because the Earth's lithosphere has higher strength than the underlying asthenosphere. Lateral density changes in the mantle appear in convection. Plate movement is believed to be driven by a succession of the motion of the seafloor apart from the extended ridge (due to variations in topography and density of the crust.
Answer:2.55 rad/s
Explanation:
Given
Diameter of ride=5 m
radius(r)=2.5 m
Static friction coefficient range=0.60-1
Here Frictional force will balance weight
And limiting frictional force is provided by Centripetal force

weight of object=mg
Equating two
f=mg




Answer:
4.535 N.m
Explanation:
To solve this question, we're going to use the formula for moment of inertia
I = mL²/12
Where
I = moment of inertia
m = mass of the ladder, 7.98 kg
L = length of the ladder, 4.15 m
On solving we have
I = 7.98 * (4.15)² / 12
I = (7.98 * 17.2225) / 12
I = 137.44 / 12
I = 11.45 kg·m²
That is the moment of inertia about the center.
Using this moment of inertia, we multiply it by the angular acceleration to get the needed torque. So that
τ = 11.453 kg·m² * 0.395 rad/s²
τ = 4.535 N·m