Answer:
1.The Sun is located at one of the foci of the planets' elliptical orbits.
2.The path of the planets around the Sun is elliptical in shape.
Explanation:
As per Kepler's law of planet motion we know that all planets revolve around the sun in elliptical path in such a way that position of Sun must be at one of the focii of the path
So all planets are in elliptical path always
Position of sun is always at one of the focus
so correct answer will be
1.The Sun is located at one of the foci of the planets' elliptical orbits.
2.The path of the planets around the Sun is elliptical in shape.
a) Solids keep shape, liquids take shape of containers but don't spill, gases take container's shape and spill out
b) if you heat gas, speed of its molecules will increase and they'll push the container's walls stronger, so the pressure will increase when the container heated
c) Heat flows from warmer to colder bodies
d) For monatomic gases it's U=1.5nRT only, molecular gas has bonds between atoms so total internal energy increases
e) Of gases
f)
m/s
g) U=5/2*nRT=37830.85 J
Answer:

Explanation:
a. Internal energy and the relative specific volume at
are determined from A-17:
.
The relative specific volume at
is calculated from the compression ratio:

#from this, the temperature and enthalpy at state 2,
can be determined using interpolations
and
. The specific volume at
can then be determined as:

Specific volume,
:

The pressures at
is:

.The thermal efficiency=> maximum temperature at
can be obtained from the expansion work at constant pressure during 

b.Relative SV and enthalpy at
are obtained for the given temperature with interpolation with data from A-17 :
Relative SV at
is

=
Thermal efficiency occurs when the heat loss is equal to the internal energy decrease and heat gain equal to enthalpy increase;

Hence, the thermal efficiency is 0.563
c. The mean relative pressure is calculated from its standard definition:

Hence, the mean effective relative pressure is 674.95kPa
Answer:
Twice
Explanation:
From the formula for velocity in a circle
V= 2πr/T
Where V is velocity
r is raduis
T is period
We see that as r increases V increases so if r is doubled V becomes doubled
Answer:
They walk 3,600 meters
Explanation:
7.5 minutes = 450 seconds.
Because they are walking at 8 meters per 1 second, multiply 8 by 450.
= 3600m