Question

The velocity of a particle at an instant is 10 m $s^{-1}$. After 3 s its velocity will becomes 16 m $s^{-1}$ . The velocity at 2 s, before the given instant will be

• A. 6 m $s^{-1}$
• B. 4 m $s^{-1}$
• C. 2 m $s^{-1}$
• D. 1 m $s^{-1}$

Answer 1

Answer: (A)

6 m $s^{-1}$

Applying first equation of motion from $B$ to $C.$

$v=u+at16=10+a\left(3\right)⟹a=2m/s^2$

Now, applying first equation of motion from $A$ to $B.,$

$v=u+at⟹10=v+2\times 2⟹v=6m/s$