Remember that
1m=100cm
8m=800cm
800m=80,000cm
4 units right and 4 units down
Answer:
distance covered in 2 hours = 80 km
distance covered in 1 hour = 80÷2 = 40 km
distance covered in 7/2 hours = 40 × 7/2
= 140 km
(3 1/2hours = 7/2 hours)
correct answer is 0.0000010075
(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).)