2.The distance travelled by a body moving with uniform acceleration in the nth second is given by Sn=3.8+0.4n,find the velocity of the body
Sn=3.8+0.4-----(eqn 1)
Sn=u+a(n-1/2)
=u+an-a/2
Sn=(u-a/2)+an------(eqn 2)
from 1 and 2
a=0.4m/s^2
u-a/2=3.8
u-0.4/2=3.8
u-0.2=3.8
u=6.0m/s
Good
To find the velocity of the body, we need to use the relationship between displacement, velocity, and time for a body moving with uniform acceleration.
Given that the distance traveled by the body in the nth second is given by Sn = 3.8 + 0.4n, we can find the displacement in the nth second by subtracting the distance traveled in the (n-1)th second from the distance traveled in the nth second.
So, the displacement in the nth second is given by:
Sn - Sn-1 = (3.8 + 0.4n) - (3.8 + 0.4(n-1))
= 3.8 + 0.4n - 3.8 - 0.4n + 0.4
= 0.4
Now, we know that velocity is the rate of change of displacement with respect to time. So, we can use this displacement in the nth second and divide it by the time interval (which is 1 second) to find the velocity:
Velocity = Displacement / Time = 0.4 / 1 = 0.4 m/s
Therefore, the velocity of the body is 0.4 m/s.