Question

If an object travels 13m in 10th second & 21min 14th second with constant acceleration than its initial speed & acceleration are
(1) u=-5, a = 2
(2) u = -6, a = 2
(3) a = 2, u = 6
(4) u = -7, a = -2​

Answer 1

Answer:

ok

Explanation:

u=5,a=2 is correct answer

Answer 2

(4)$u=-7,a=2$ acceleration and initial speed of object travel.

Explanation:

• The object travels with constant acceleration.

• Using,$\[{{S}_{n}}$  formula to find its acceleration and initial speed

                  $\[{{S}_{n}}=u+21a(2n-1)\]$

         where a is the acceleration of the body and u is the initial velocity.

• An object travels 13m in 10th second,

                   $\[{{S}_{n}}=13,n=10$

                    $13=u+10a$               (1)

• An object travels 21min 14th second,

                    $\[{{S}_{n}}=21,n=14$

                     $21=u+14a$                (2)

• Solving equation (1) and equation (2) ,we get

                   $a=2\frac{m}{s^{2} }$

                    $u=-7\frac{m}{s }$

• Hence, these are the acceleration and initial speed of object travel.