Answer:
1225 J
Explanation:
The Gravitational potential energy (PEG) gained by a mass lifted above the ground is given by

where
m is the mass
g = 9.8 m/s^2 is the acceleration due to gravity
h is the height at which the object has been lifted
In this problem, we have
m = 250 kg
h = 0.5 m
So, the PE of the object is

Answer:
a ) 11.1 *10^3 m/s = 39.96 Km/h
b) T_{o2} =1.58*10^5 K
Explanation:
a)
= 11.1 km/s =11.1 *10^3 m/s = 39.96 Km/h
b)
M_O2 = 32.00 g/mol =32.0*10^{-3} kg/mol
gas constant R = 8.31 j/mol.K

So, 
multiply each side by M_{o2}, so we have

solving for temperature T_{o2}

In the question given,

T_{o2} =1.58*10^5 K