The position of a particle as it moves along an y axis is given by y = (2.0cm)sin(πt/4), with t in second and y in centimeters.
a.what is the average velocity of the particle between t = 0 and t = 2.0 s?
b.what is the instantaneous velocity of the particle at t = 0, 1.0, and 2.0 s?
c.what is the average acceleration of the particle between t = 0 and t = 2.0 s?
d.what is the instantaneous acceleration of the particle at t = 0, 1.0, and 2.0 s?

Respuesta :

Part a)

At t = 0  the position of the object is given as

[tex] x = 0[/tex]

At t = 2

[tex] x = 2 sin(\pi/2) = 2cm[/tex]

so displacement of the object is given as

[tex]d = 2 - 0 = 2cm[/tex]

so average speed is given as

[tex]v_{avg} = \frac{2}{2} = 1 cm/s[/tex]

Part b)

instantaneous speed is given by

[tex] v = \frac{dy}{dt}[/tex]

[tex]v = 2cos(\pi t/4 ) * \frac{\pi}{4}[/tex]

now at t= 0

[tex]v = \frac{\pi}{2} cm/s[/tex]

at t = 1

[tex] v = 2 cos(\pi/4) * \frac{\pi}{4}[/tex]

[tex]v = \frac{\pi}{2\sqrt2}[/tex]

at t = 2

[tex]v = 0[/tex]

Part c)

Average acceleration is given as

[tex]a_{avg} = \frac{v_f - v_i}{t}[/tex]

[tex]a_{avg} = \frac{0 - \frac{\pi}{2}}{2}[/tex]

[tex]a = -\frac{\pi}{4} cm/s^2[/tex]

Part d)

Now for instantaneous acceleration

As we know that

[tex]a =- \omega^2 y[/tex]

at t = 0

[tex] a = -\frac{\pi^2}{16} * 0 = 0 cm/s^2[/tex]

at t = 1

[tex]y = \sqrt2 cm[/tex]

now we have

[tex]a = -\frac{\pi^2}{16}*\sqrt2[/tex]

At t = 2 we have

[tex] y = 2 cm[/tex]

[tex]a = -\frac{\pi^2}{16}*2[/tex]

[tex]a = -\frac{\pi^2}{8}[/tex]

so above is the instantaneous accelerations