Answer:
<h3>30.405°C</h3>
Explanation:
Using the formula for heart capacity;
Q = mcΔt
m is the mass = 150g = 0.15kg
initial temperature = 22°C
Quantity of heat = 3240J = 3.24kJ
specific heat capacity of ethanol = 2.57 [kJ/kg K]
Substitute and get the final temperature
3.240 = 0.15(2.57)(T - 22)
3.240 = 0.3855(T-22)
3.240/0.3855 = T - 22
8.405 = T - 22
T = 22+8.405
T = 30.405°C
Hence the final temperature of the ethanol if 3240 J was needed to raise the temperature of the ethanol is 30.405°C
C) The longer the line, the greater the magnitude of the vector. As for the direction, just think of a compass.
The answer is B. On a sunny day, the air over a lake will be cooler than the air over the bordering land.
By looking at the potential energies before and after the reaction, we can tell that the reaction is exothermic (final < initial) or endodermic (final > initial).
Also, the amount of activation energy gives an idea of the external energy required to initiate the reaction (for example, by heating the reactants).
Furthermore, by the same principle, we can also deduce the activation energy for the reverse reaction.
If a catalyst is available, the diagram will show a reduced activation energy, compared to a reaction without catalyst. However, it will also show that the catalyst does not alter the initial and final energies of the reaction.
<h2>
After 26.28 seconds projectile returns 26.28 seconds.</h2>
Explanation:
Initial velocity = 450 ft/s = 137.16 m/s
Angle, θ = 70°
Consider the vertical motion of projectile,
When the projectile return to the ground we have
Displacement, s = 0 m
Acceleration, a = -9.81 m/s²
Initial velocity, u = 137.16 x sin70 = 128.89 m/s
Substituting in s = ut + 0.5 at²
s = ut + 0.5 at²
0 = 128.89 x t + 0.5 x (-9.81) x t²
t² - 26.28 t = 0
t ( t- 26.28) = 0
t = 0 s or t = 26.28 s
After 26.28 seconds projectile returns 26.28 seconds.
