(d) The particle moves in the positive direction when its velocity has a positive sign. You know the particle is at rest when
and
, and because the velocity function is continuous, you need only check the sign of
for values on the intervals (0, 3) and (3, 6).
We have, for instance
and
, which means the particle is moving the positive direction for
, or the interval (3, 6).
(e) The total distance traveled is obtained by integrating the absolute value of the velocity function over the given interval:

which follows from the definition of absolute value. In particular, if
is negative, then
.
The total distance traveled is then 4 ft.
(g) Acceleration is the rate of change of velocity, so
is the derivative of
:

Compute the acceleration at
seconds:

(In case you need to know, for part (i), the particle is speeding up when the acceleration is positive. So this is done the same way as part (d).)
<span>−8x+5−2x−4+5x
= -5x + 1
so when x = 2 then
</span>-5x + 1
= -5(2) + 1
= -9
hope it helps
step 1
convert pounds to ton
1 ton------> 2204.62 lb
<span>each crate weighs 80 pounds
so
by proportion
1/2204.62=x/80
x=80/2204.62-----> x=0.036 ton
each crate weighs 0.036 ton
step 2
divide 2 ton by 0.036
2/0.036=55.11 crate----------> 55 crate
the answer is
</span>the greatest number of crates that can be loaded onto the elevator is <span>55
alalternative method
</span>step 1
convert ton to pounds
1 ton------> 2204.62 lb
a freight elevator has a weight limit of 2 ton
2 *2204.62 -----> 4409.24 lb
step 2
each crate weighs 80 pounds
divide 4409.24 by 80
4409.24/80=55.11 crate----------> 55 crate
<span>
</span>
386 x 21 = 8.106
I hope you got a good grade on your assignment!!! :D