Question

a particle is moving with uniform acceleration in eighth and thirteenth second after starting it moves through 255cm to 225cm . find its initial velocity and its acceleration​

Answer 1

Answer:

Explanation:

Given A particle is moving with uniform acceleration in eighth and thirteenth second after starting it moves through 255 cm to 225 cm . find its initial velocity and its acceleration

We know that distance or s for nth sec is given by

         S = u + ½ a (2n – 1)

Now u = ? and a = ?

So distance in 8 th sec  = u + 1/2 a (2(8) – 1)

             255 = u + 1/2 x 15 a -------------(1)

Distance in 13 th sec = u + 1/2 a (2(13) – 1)

            225 = u + 1/2 x 25 a-----------(2)

Subtracting 1 from 2 we get

         - 30 = U + 25 a / 2 – (4 + 15 a /2)

            5a = - 30

               a = - 6 cm /s^2

Substituting in 1 we get

255 = u + ½ x 15 (- 6)

 u = 300 cm / s

initial velocity is 300 cm /s and its acceleration​ is - 6 cm /s^2