Question

The position (x) of a particle moving along x-axis varies with time (t) as shown in figure. The average acceleration of particle in time interval t = 0 to t = 8 s is.

• A. 3 $m/s^2$
• B. -5 $m/s^2$
• C. -4 $m/s^2$
• D. 2.5 $m/s^2$

Answer 1

Answer: (B)

average acceleration $a=\frac{v_2-v_1}{t}$ eq(1)..

intial velocity is the slop of the graph in between the 0 to 2sec

$v_1=\frac{40}{2}=20m{s}^{-1}$

final velocity os the slop of the graph in between the 6-8sec

$v_2=-\frac{40}{2}=-20m{s}^{-1}$

total time is 8sec.

put v_{1}and v_{2} in eq(1)

$a=\frac{-20-20}{8}=\frac{-40}{8}=-5m{s}^{-2}$

Hence the answer is B option.