If a body starts from rest and travels 120 m in the 8th second, the acceleration is :

To solve this problem, we need to use the equation of motion that relates distance, acceleration, and time. The equation is:

s = ut + 1/2at^2

where: s = distance traveled u = initial velocity t = time a = acceleration

Given that the body starts from rest, the initial velocity (u) is 0. The distance traveled (s) in the 8th second is 120 m. However, we need to be careful here. The equation of motion gives the total distance traveled from the start until a given time, not the distance traveled in a particular second.

So, we need to find the total distance traveled until the 7th second and subtract it from the total distance traveled until the 8th second.

Let's denote: s7 = total distance until the 7th second s8 = total distance until the 8th second

We know that s8 - s7 = 120 m.

From the equation of motion, we have:

s7 = 1/2a(7^2) = 24.5a s8 = 1/2a(8^2) = 32a

Substituting these into the equation s8 - s7 = 120 m, we get:

32a - 24.5a = 120 7.5a = 120 a = 120 / 7.5 a = 16 m/s^2

So, the acceleration of the body is 16 m/s^2.