a car, starting from rest , began moving in straight line and its velocity is given by v= (8t2+6t) m/s then its displacement at t=9 equals

To find the displacement at a specific time, we need to integrate the velocity function with respect to time.

∫v(t) dt = ∫(8t^2 + 6t) dt = 8(t^3/3) + 6(t^2/2) + C

where C is the constant of integration.

Since the car started from rest, its initial position is 0. Therefore, the displacement at t=9 can be found by evaluating the above expression at t=9 and subtracting the initial position:

displacement at t=9 = 8(9^3/3) + 6(9^2/2) - 0 = 2052 meters

Therefore, the displacement of the car at t=9 is 2052 meters.

1944 + 243 = 2187

That is correct.

2187 is not 2052 meters

You are correct. I apologize for the mistake in my previous response. I will recalculate the displacement at t=9:

∫v(t) dt = ∫(8t^2 + 6t) dt = 8(t^3/3) + 6(t^2/2) + C

At t=0, the car starts from rest, therefore, initial velocity = u = 0
Therefore, the constant of integration is C=0.

Putting this value in above equation we get,

Displacement (d) = 8(9^3/3) + 6(9^2/2) + 0 = 2187 meters

Therefore, the displacement of the car at t=9 is 2187 meters. I apologize for any confusion caused.

Whew !

I'm sorry again for any confusion caused. Thank you for bringing it to my attention.