Answer:
The force is equal to 489.87 [N]
Explanation:
We need to make a free body diagram whe we can see the forces acting over the parachutist. In the attached image we can see the sketch of the free body diagram.
First we use the analysis of forces equal to mass by acceleration to be able to determine the equation with the term of the resistance force.
Then we have to find the acceleration to be able to apply it in the equation of the resistance force of the parachute. The acceleration can be found using the following kinematics equation
Note: here the acceleration is positive because the direction of the acceleration is towards the movement
Therefore the resistance force is 489.87 [N] or 49.93[kg-f]
Note: We can see that the resistance force of the parachute is almost equal to the equivalent of the weight of the parachutist, although its value is lower in this way it is explained by the fact that the system is not in balance and the person descends.
Answer:
C.
Explanation:
The acceleration of an object can be found using the equation:
where
v is the final velocity
u is the initial velocity
t is the time it takes for the velocity to change from u to v
In this problem:
u = 30 m/s is the initial velocity of Angelica
v = 84 m/s is the final velocity
t is the time
Substituting into the equation, we find the acceleration:
Answer:
The final equilibrium T_{f} = 25.7[°C]
Explanation:
In order to solve this problem we must have a clear concept of heat transfer. Heat transfer is defined as the transmission of heat from one body that is at a higher temperature to another at a lower temperature.
That is to say for this case the heat is transferred from the iron to the water, the temperature of the water will increase, while the temperature of the iron will decrease. At the end of the process a thermal balance is found, i.e. the temperature of iron and water will be equal.
The temperature of thermal equilibrium will be T_f.
The heat absorbed by water will be equal to the heat rejected by Iron.
Heat transfer can be found by means of the following equation.
where:
Qiron = Iron heat transfer [kJ]
m = iron mass = 200 [g] = 0.2 [kg]
T_i = Initial temperature of the iron = 300 [°C]
T_f = final temperature [°C]
Cp_iron = 437 [J/kg*°C]
Cp_water = 4200 [J/kg*°C]