kinematics

the distance travelled by a body in the n th second is
(2n+3). find initial velocity and acceleration.

1 Answers

206

Sayantan Hazra ·2013-05-19 11:36:03

The distance travelled in the n the second means the distance travelled by the body in between (n-1) and n seconds.

So,x_n-1 = u(n-1) + 12a(n-1)²

and

x_n = un + 12an²

Now, ATQ, x_n - x_n-1 = 2n + 3
or, u + 12a[n² - (n-1)²] = 2n + 3
or, u + 12a(2n - 1) = 2n + 3
or, (u - a2) + an = 2n + 3

Now simply compare co effecients on both sides to find the a, and then you can find u.

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