Question

The velocity of a skateboard is v(t) = t^2 - 4 t + 3 m/s when moving in a straight line.

A. Find the the change in displacement of the skateboard between 4 seconds and 6 seconds. (Note this may or may not be negative, meaning it goes in the opposite direction, if so then be sure to include the sign.)

Change of displacement = m

B. Find the acceleration of the skateboard when t = 6 seconds.

Acceleration = m/s^2

Answer 1

A. Integrate the velocity
x = (t^3)/3-2t+3t
substitute 4 and 6

[(4^3)/3 - 2(4)+3(4)] - [(6^3)/3 - 2(6)+3(6)] = m?

B. get the derivatives of velocity
a = 2t^2 - 4
substitute t=6

2(6)^2-4 = m/s^2?

Answer 2

a = 2t-4, not 2t^2-4