Particle motion

**live_laugh_luv27** · October 25th 2009, 11:39 AM

Particle moves along vertical axis, position at any time t greater than or equal to 0 is given by the function $s(t) = \frac{1}{3}t^3-3t^2+8t-4$ , $s$ is centimenters and $t$ is seconds.

a. Find the displacement during the first 6 seconds

b. Find the average velocity during the first 6 seconds

c. Find expressions for velocity and acceleration at time $t$

d. For what values of $t$ is the particle moving downward?

Here are my answers...are they correct? thanks.

a. 12

b. -10

c. $v(t) = t^2-6t+8$
$<br /> a(t)=2t-6<br />$

d. $t$ is less than 0? I'm not sure how to do this one..

**skeeter** · October 25th 2009, 12:05 PM

Originally Posted by live_laugh_luv27

Particle moves along vertical axis, position at any time t greater than or equal to 0 is given by the function $s(t) = \frac{1}{3}t^3-3t^2+8t-4$ , $s$ is centimenters and $t$ is seconds.

a. Find the displacement during the first 6 seconds

b. Find the average velocity during the first 6 seconds

c. Find expressions for velocity and acceleration at time $t$

d. For what values of $t$ is the particle moving downward?

Here are my answers...are they correct? thanks.

a. 12 ok

b. -10 no ... avg v = displacement/time

c. $v(t) = t^2-6t+8$ ok
$<br /> a(t)=2t-6<br />$ ok

d. $t$ is less than 0? I'm not sure how to do this one..

find the interval where v(t) < 0

...

**live_laugh_luv27** · October 25th 2009, 12:17 PM

Originally Posted by skeeter

...

so,
b would be 2 sec/centimeter?

and would d be all real numbers less than 0.64?

**skeeter** · October 25th 2009, 01:44 PM

Originally Posted by live_laugh_luv27

so,
b would be 2 sec/centimeter? cm/sec

and would d be all real numbers less than 0.64?

$t^2 - 6t + 8 = 0$

$(t - 2)(t - 4) = 0$

$v(t) < 0$ on the interval $2 < t < 4$

Thread: Particle motion

LinkBack

Thread Tools

Display

Particle motion

Similar Math Help Forum Discussions

particle motion

Particle Motion

Particle motion

Particle motion

motion of a particle

Search Tags