Five graphs (labelled A–E in the source figure) represent possible variations of velocity v against time t for a ball thrown vertically upwards and returning under constant downward acceleration. Which plotted graph(s) is/are correct? Image
Options

Question

Five graphs (labelled A–E in the source figure) represent possible variations of velocity v against time t for a ball thrown vertically upwards and returning under constant downward acceleration. Which plotted graph(s) is/are correct? Image

Options

G1 Physics · Accepted Answer

Step 1: Choose upward as the positive direction. The gravitational acceleration is constant, a = −g. Step 2: Integrate a = dv/dt to get v(t) = u − gt, a straight line with negative slope. Step 3: Initially v = +u; at the highest point v = 0; during descent v becomes negative. Step 4: Only graph C shows a straight velocity–time line decreasing across zero into negative values. Final answer: Graph C only (Option C).