Answer:
(a) The average speed is 0.85 milles/minute
(b) The average velocity is zero
Explanation:
In order to answer part (a) and (b) you have to apply the formulas for average speed and average velocity which are:
<em>-Average speed formula:</em>

where d is the total distance traveled and t is the tota time
Replacing the given values:
milles/minute
Notice that you have to replace the total distance, which is 14 milles for the go plus 14 milles for the return. The same for the total time.
<em>-Average velocity formula:</em>
V = Δx/Δt
Where V is the velocity vector, Δx is the displacement and Δt is the change in time
V= 
Where X2 is the final position and X1 is the initial position
In this case X1= 0 i and X2=0 i (i is the unit vector in the x direction). So, the displacement is zero.
Therefore, the average velocity is:
V= 0 i [milles/minute]
False. That's why sound cannot be heard in space.
Answer:
Apply Newton's second law in the moving direction.
Explanation:

Friction force applies in the opposite direction of motion; as a restriction.
a) At a position of 2.0m, the Initial energy is
all made up of the potential energy=m*g*hi<span>
and meanwhile at 1.5 all its energy is also potential energy=m*g*hf
The percentage of energy remaining is E=m*g*hi/m*g*hf x 100
and since mass and gravity are constant so it leaves us with
just E=hi/hf
which 1.5/2.0 x100= 75% so we see that we lost 25% of the
energy or 0.25 in fraction
b) Here use the equation vf^2=vi^2+2gd
<span>where g is gravity, vf is the final velocity and vi is the
initial velocity while d is the distance travelled
so in here we are looking for the vi so let us isolate that
variable
we know that at maximum height or peak, the velocity is 0 so
vf is 0
therefore,</span></span>
vi =sqrt(-2gd) <span>
vi =sqrt(-2x-9.81x1.5) </span>
<span>vi =5.4 m/s
<span>c) The energy was converted to heat due to friction with the
air and the ground.</span></span>
From among the choices provided, the more appropriate
answer is ' T ', the initial letter often used to represent
words that include 'true', 'truth', 'trust', etc., (as well as
'tree', 'train', 'transmit', 'Transylvania', 'trachea', 'travesty',
and 'trick', which are irrelevant to the present discussion).
This response is the most fitting and appropriate, because
the statement that precedes the list of allowable choices is
exemplary in its accuracy and veracity. An ion can, in fact,
have a positive or negative charge, although the same ion
cannot have both.