Question

A body moves in a straight line along X-axis, its distance from the
origin is given by the equation : x = 12 - 4t, where x is in metre and tis in
second. Find the average velocity in the interval from t= 0 tot = 1
(a) 5 m/s
(b) 3 m/s
(c) 5 m/s
(d) 3 m/s
​

Answer 1

Answer:

A body is moving in a straight line along x-axis its distance from the origin is given by the equation x=at^2 bt^3.

Equation is x= t^2 - 4t + 6

x= t^2 - 4t +6

As we know that,

v= dx/dt

Therefore,

v = d (t^2 - 4t + 6)/dt = (2t - 4)

On substituting value of t as 0 and 3 sec we get

u= -4 m/s

v= 2 m/s

Now,

Average Speed= u+v/2

=>-4+2/2

= -2/2

= -1 m/s

Average Speed= -1 m/s.

So, speed is not in negative.

[So, Average Speed= 1 m/s. ]