Question

question 3
wegener attempted to explain the movement of continents but could not identify a source of force strong enough. what did scientists eventually identify as the primary energy source that drives the movement of earths plates?
convection
friction
gravity
volcanoes

Explanation:

Convection currents in the Earth's mantle drive plate - tectonic movement. Heat from the Earth's interior causes the mantle material to move in a circular pattern, which in turn moves the overlying tectonic plates. Friction is a resistive force, not a driving energy source. Gravity acts on the mass of the plates but is not the primary driving energy. Volcanoes are a result of plate - tectonic activity, not the driving force behind it.

Answer:

Convection