Question

If velocity of a particle is given by $v=10+2t^{2}m/s$. The average acceleration between $2$ and $5s$ is:

• A. $2m/s^2$
• B. $4m/s^2$
• C. $12m/s^2$
• D. $14m/s^2$

Answer 1

The correct option is D $14m/s^2$

Velocity when $t=2s$ is $v_2=10+2\times 4=18m/s$

Velocity when $t=5s$ is $v_5=10+2\times 25=60m/s$

so change in velocity will be $\Delta v=60-18=42m/s$

time taken is $\Delta t=5-2=3s$

so the average acceleration will be $a=\frac{\Delta v}{\Delta t}=\frac{42m/s}{3s}=14m/s^2$