Answer:
D. gravity, friction, and an applied force.
Explanation:
There are 4 forces that act on an airplane in motion and they are:
Gravity and drag:
It acts in a downward direction—toward the center of the Earth.
Lift:
It is the force that acts at a right angle to the direction of motion through the air. Lift is created by differences in air pressure.
Thrust:
It is the force that propels a flying machine in the direction of motion.
Answer:
65,000 g/mol, 43,000g/mol and 22,000 g/mol.
Explanation:
The explanation can be found in the attachment
<span>S(s)+O2(g)→SO2(g), ΔHâ = -296.8kJ
SO2(g)+12O2(g)→SO3(g) , ΔHâ = -98.9kJ
H2(g) + 1/2 O2 (g) --------> H2O(l)ΔHâf = -285.8kJ
SO3(g) + H2O(l) --------> H2SO4, ΔHâ = -227.8 kJ .
All above steps are involved in the formation of H2SO4, therefore delta Hf for H2SO4 is [ -296.8+ (-98.9)+ (-285.8) +(-227.8)] = - 909.3 kj/mol
The energy required to form 1 mol H2SO4 fom its elements is - 909.3 kj / mol</span>
A hot summer day it could go up in flames. And on a cold day it expands.