Answer:
ΔH°comb=-5899.5 kJ/mol
Explanation:
First, consider the energy balance:
Where
is the calorimeter mass and
is the number of moles of the samples;
is the combustion enthalpy. The energy balance says that the energy that the reaction release is employed in rise the temperature of the calorimeter, which is designed to be adiabatic, so it is suppose that the total energy is employed rising the calorimeter temperature.
The product is the heat capacity, so the balance equation is:
So, the enthalpy of combustion can be calculated:
I will be happy to solve any doubt you have.
Answer:
Tension= (g=acceleration of gravity)
Explanation:
Given that,
A 5Kg and 10Kg are attached by a cable suspended over a pulley.
As 10Kg > 5Kg , the 10 kg mass accelerates down and the 5kg mass accelerates up, let it be a. Let the tension in the cable be T.
So, the equations of motion are
Now adding them we get,
Substituting them back in the equation we get,
Answer:
1000 N
Explanation:
First, we need to find the deceleration of the running back, which is given by:
where
v = 0 is his final velocity
u = 5 m/s is his initial velocity
t = 0.5 s is the time taken
Substituting, we have
And now we can calculate the force exerted on the running back, by using Newton's second law:
so, the magnitude of the force is 1000 N.