Velocity and acceleration: displacement is given by s =4t^3−21t^2 +30t (t≥0).

[momandala]

Velocity and acceleration: displacement is given by s =4t^3−21t^2 +30t (t≥0).

An object moves along a straightline. Its displacement s in metres from its starting point tat time t (in seconds) is given by s =4t^3−21t^2 +30t (t≥0).
Find expressions for thev elocity and acceleration of the object at time t,and hence calculate the numerical values of the velocityand the acceleration at time t =3.[ 3 ]
findany times at whichthe velocity of theobject is zero.
I'm stuck on what to do in the beginning portion of the question. Need help ASAP. Thank you.

 

[Deleted member 4993]

An object moves along a straightline. Its displacement s in metres from its starting point tat time t (in seconds) is given by s =4t^3−21t^2 +30t (t≥0).
Find expressions for thev elocity and acceleration of the object at time t,and hence calculate the numerical values of the velocityand the acceleration at time t =3.[ 3 ]
findany times at whichthe velocity of theobject is zero.
I'm stuck on what to do in the beginning portion of the question. Need help ASAP. Thank you.

Hint: v = ds/dt and a = dv/dt

What are your thoughts?

Please share your work with us ...even if you know it is wrong

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