For one-dimensional motion, the velocity ($v$) of a particle must be a unique function of time ($t$). This means that for any specific instant in time, there can only be one corresponding velocity value. Graphically, this implies that any vertical line drawn on a velocity-time ($v-t$) graph must intersect the curve at most once.
A valid $v-t$ graph must represent velocity as a unique function of time. Graph 1 satisfies this condition. Assuming the empty Graph 4 represents a particle at rest ($v=0$), it also represents valid one-dimensional motion. Graphs 2 and 3 are invalid because they do not represent velocity as a unique function of time.
Therefore, Graph 1 and Graph 4 can possibly represent one-dimensional motion.
A body initially at rest and sliding along a frictionless track from a height '$h$' (as shown in figure) just completes a vertical circle of diameter AB = $d$. The height '$h$' is equal to
Three blocks of masses $m_1 = 2\text{ kg}$, $m_2 = 3\text{ kg}$ and $m_3 = 5\text{ kg}$ are placed on a horizontal frictionless surface and a force of 30N pulls the system as shown below. The value of tension in the string between $m_2$ and $m_3$ will be
A uniform rod $AB$ is suspended from a point $P$, at a variable distance $x$, from $A$, as shown in figure. To make the rod horizontal, a mass '$m$' is suspended from its end $A$. Which set of variables will give a straight line when they are plotted?

A particle of mass $m$ is suspended from a point O by a string of length $R$. It is given a velocity $u = 3\sqrt{gR}$ at the bottom. The difference in tension at point $B$ and at the point $C$ is
The moment of inertia of a thin disc about axes $a, b, c, d$ are $I_{1}, I_{2}, I_{3}$ and $I_{4}$ respectively, as shown in figure. If the moment of inertia about an axis passing through the centre and perpendicular to the plane of the disc is $I$ then,
In the given figure the blocks $A$, $B$ and $C$ weigh 4 kg, 6 kg and 8 kg respectively. The co-efficient of sliding friction between any two surfaces is 0.5. The force $\vec{F}$ required to slide the block $C$ with constant speed is ______ N. (Use $g = 10 \text{ m/s}^2$)
