Question

The velocity-time graph of a particle moving along a straight line in a given time interval is as shown in figure. Then speed of the particle (with increase in time starting from $t=0sec$ )

• A. increases continuously
• B. first increases and then decreases
• C. decreases continuously
• D. first decreases and then increases

Answer 1

The correct option is D first decreases and then increases

From $t=0sec$ to $t=t_{0}sec$
The slope of the graph is positive(i.e.$\frac{dv}{dt}=+ve$) so, acceleration is positive and velocity is negative in this time interval.
Therefore, the speed of the particle will decrease first.


After $t=t_0\text{sec}$ both acceleration as well as velocity are positive so, the speed will increase after $t=t_0\text{sec}$.


Hence speed of the particle will decrease first and then increases.