Thread: average velocity over the time interval

1. average velocity over the time interval

A stone is tossed in the air from ground level with an initial velocity of 15m/s. Its height at time t is h(t) = 15t - 4.9t^2 m.

Compute the stone's average velocity over the time interval [1, 3.5].Average velocity ?

I tried to solve it, but when time is '3.5' v became minus...

2. Originally Posted by wnsghkghk
A stone is tossed in the air from ground level with an initial velocity of 15m/s. Its height at time t is h(t) = 15t - 4.9t^2 m.

Compute the stone's average velocity over the time interval [1, 3.5].Average velocity ?

I tried to solve it, but when time is '3.5' t became minus...
$\bar{v} = \frac{h(3.5) - h(1)}{3.5 - 1}
$

$\bar{v} = \frac{h(3.5) - h(1)}{3.5 - 1} = -7.05$ m/s

3. Originally Posted by wnsghkghk
A stone is tossed in the air from ground level with an initial velocity of 15m/s. Its height at time t is h(t) = 15t - 4.9t^2 m.

Compute the stone's average velocity over the time interval [1, 3.5].Average velocity ?

I tried to solve it, but when time is '3.5' t became minus...
"t" is 3.5 which is NOT negative. I presume you mean that v is negative- and there is nothing wrong with that.

4. ughhhhhhhhh I put just 7.05 not -7.05