Answer:
a.Beth
b.2232 s
Explanation:
We are given that
Distance,d=400 mi
Speed of Alan,v=45 mph
Speed of Beth,v'=55 mph
a.Time =
Using the formula
Time taken by Alan=
Time taken by Beth=
Alan will reach San Francisco at 4:53 PM
Beth will reach San Francisco at 4:16 PM
Beth will reach before Alan.
b.Difference between time=8.89-7.27=1.62 hr
t=1.62 hr
1.62-1=0.62 hr
0.62 hr=
Hence, Beth has to wait 2232 s for Alan to arrive .
At the "very top" of the ball's path, there's a tiny instant when the ball
is changing from "going up" to "going down". At that exact tiny instant,
its vertical speed is zero.
You can't go from "rising" to "falling" without passing through "zero vertical
speed", at least for an instant. It makes sense, and it feels right, but that's
not good enough in real Math. There's a big, serious, important formal law
in Calculus that says it. I think Newton may have been the one to prove it,
and it's named for him.
By the way ... it doesn't matter what the football's launch angle was,
or how hard it was kicked, or what its speed was off the punter's toe,
or how high it went, or what color it is, or who it belongs to, or even
whether it's full to the correct regulation air pressure. Its vertical speed
is still zero at the very top of its path, as it's turning around and starting
to fall.
Answer: 
Explanation:
Density 
is defined as a relation between the mass 
and the volume 
of a substance, body or object:
(1)
We already know the mass of the rectangular solid 
, but we have to calculate its volume with the following dimensions:
If the expression for volume in this case is:
(2)
Then the volume of the unknown solid is:
(3)
Substituting (3) in (1):
(4)
We finally obtain the density of the solid:
(5)
