Question

A body moving with a constant acceleration travels the distances 3 m and 8 m respectively in 1 s and 2 s. Calculate the initial velocity.

• A. $4m{s}^{-1}$
• B. $0m{s}^{-1}$
• C. $2m{s}^{-1}$
• D. $1m{s}^{-1}$

Answer 1

Answer: (C)

$2m{s}^{-1}$

$a=ut+\frac{1}{2}a{t}^2$

Putting the values,
$3=u\times 1+\frac{1}{2}a\times 1^2$
$a=6-2u..............\left(i\right)$

Similarly, $8=u\times 2+\frac{1}{2}a\times 2^2$
$a=4-u.................\left(ii\right)$

Equating (i) and (ii),

$6-2u=4-u$
$u=2m/s$