Question

a v-t line above the axis indicates:
positive velocity
stopped
negative displacement
zero acceleration always

Explanation:

In a velocity - time (v - t) graph, the vertical axis (y - axis) represents velocity. The sign of the velocity (positive or negative) is determined by its position relative to the time axis (x - axis). If the v - t line is above the time axis, it means that the velocity value is positive.

• Option "stopped" is incorrect because when an object is stopped, the velocity is zero, and the v - t line would be on the time axis (v = 0), not above it.
• Option "negative displacement" is incorrect. Displacement from a v - t graph is the area under the v - t curve. A positive velocity (v - t line above the axis) over a time interval will result in a positive displacement (since area with positive velocity contributes positively to displacement), not negative.
• Option "zero acceleration always" is incorrect. The slope of the v - t graph represents acceleration. A v - t line above the axis can have a non - zero slope (i.e., non - zero acceleration, like in the case of a straight line with a non - zero slope representing constant acceleration, or a curved line representing changing acceleration). It does not imply zero acceleration always.

Answer:

A. positive velocity