Answer:
The value is 
Explanation:
From the question we are told that
The molar mass of hydrazine is 
The initial temperature is 
The final temperature is 
The specific heat capacity is ![c_h = 0.099 [kJ/(mol K)] = 0.099 *10^3 J/(mol/K)](https://tex.z-dn.net/?f=c_h%20%20%3D%20%200.099%20%5BkJ%2F%28mol%20K%29%5D%20%3D%200.099%20%2A10%5E3%20J%2F%28mol%2FK%29)
The power available is 
The mass of the fuel is 
Generally the number of moles of hydrazine present is

=> 
=> 
Generally the quantity of heat energy needed is mathematically represented as
=>
=>
Generally the time taken is mathematically represented as

=> 
=> t = 2480505.6377 s
Converting to hours

=> 
The heat capacity and the specific heat
Explanation:
In order to find out if the keys will reach John or not, we can use the formula of projectile motion to find the maximum height reached by the keys:
H = V²Sin²θ/2g
where,
V = Launch Speed = 18 m/s
θ = Launch Angle = 40°
g = 9.8 m/s²
Therefore,
H = (18 m/s)²[Sin 40°]²/(2)(9.8 m/s²)
H = 6.83 m
Hence, the maximum height that can be reached by the projectile or the keys is greater than the height of John's Balcony(5.33 m).
Therefore, the keys will make it back to John.