Question

Position of a particle moving along $x-$ axis is given by $x=3(2t-3)+4(2t-3{)}^2$
Which of the following is correct about the particle?

• A. Initial speed is $21$ $m/s$
• B. Initial speed is $18$ $m/s$
• C. Initial speed is $42$ $m/s$
• D. Acceleration is $8$ $m/s$

Answer 1

The correct option is C Initial speed is $42$ $m/s$

$x=3(2t-3)+4(2t-3{)}^2$

$\frac{dx}{dt}=6+8(2t-3)2$

At $t=0$

$V_i=-42$ $m/sec$