A particle moves according to the law of motion s(t) = t^{3}-8t^{2}+2t, where t is measured in seconds and s in feet.

(a) Find the velocity at time t.
(b) What is the velocity after 3 seconds?
(c) When is the particle at rest?

Respuesta :

Answer:

a) [tex]v(t) = 3t^{2} - 16t + 2[/tex]

b) The velocity after 3 seconds is -3m/s.

c) [tex]t = 0.13s[/tex] and [tex]t = 5.2s[/tex].

Step-by-step explanation:

The position is given by the following equation.

[tex]s(t) = t^{3} - 8t^{2} + 2t[/tex]

(a) Find the velocity at time t.

The velocity is the derivative of position. So:

[tex]v(t) = s^{\prime}(t) = 3t^{2} - 16t + 2[/tex].

(b) What is the velocity after 3 seconds?

This is v(3).

[tex]v(t) = 3t^{2} - 16t + 2[/tex]

[tex]v(3) = 3*(3)^{2} - 16*(3) + 2 = -19[/tex]

The velocity after 3 seconds is -3m/s.

(c) When is the particle at rest?

This is when [tex]v(t) = 0[/tex].

So:

[tex]v(t) = 3t^{2} - 16t + 2[/tex]

[tex]3t^{2} - 16t + 2 = 0[/tex]

This is when [tex]t = 0.13s[/tex] and [tex]t = 5.2s[/tex].