The Total solution for NCERT class 6-12
The following figure gives a speed-time graph of a particle in motionalong a constant┬аdirection. Three equal intervals of time are shown. Inwhich interval is the average acceleration greatest in magnitude? In whichinterval is the average speed greatest? Choosing the positive direction as theconstant direction of motion, give the signs of v and a in the three intervals.What are the accelerations at points A, B, C and D?
The change in thespeed with time is maximum in interval 2. Therefore, the average accelerationis greatest in magnitude in interval 2.
The average speed ismaximum in interval 3
The sign of velocityis positive in interval 1, 2 and 3. The acceleration depends on the slope. Theacceleration is positive in interval 1 and interval 3 as the slope is positive.The acceleration is negative in interval 2 as the slope is negative.
Acceleration at A, B,C and D is zero since the slope is parallel to the time axis at these instants.