Answer:
Introduction:
In this report, we will examine whether the 100 square meter parachutes with a drag coefficient of 1.5 are suitable for dropping 700-kilogram parcels from a plane at a refugee camp. The main concern is that the parcels cannot hit the ground at a velocity of more than 5 meters per second without damaging the contents.
Calculation:
To determine whether the 100 square meter parachutes with a drag coefficient of 1.5 are suitable, we need to calculate the terminal velocity of the parcels. The terminal velocity is the maximum velocity that the parcels can reach when they are falling through the air. We can calculate the terminal velocity using the following equation:
Vt = sqrt((2mg)/(ρACd))
Where:
Vt is the terminal velocity
m is the mass of the parcel (700 kg)
g is the acceleration due to gravity (9.8 m/s^2)
ρ is the air density (1.22 kg/m^3)
A is the area of the parachute (100 m^2)
Cd is the drag coefficient (1.5)
Substituting these values into the equation, we get:
Vt = sqrt((2 x 700 x 9.8)/(1.22 x 100 x 1.5)) = 52.0 m/s
This means that without any parachute, the parcel would hit the ground with a velocity of 52 m/s. However, the parachutes are designed to provide air resistance, which will slow down the parcels.
To determine whether the parachutes are suitable, we need to calculate the velocity at which the parcels will hit the ground when they are attached to the parachutes. We can use the following equation to calculate the force of air resistance:
F = (1/2)ρAv^2Cd
Where:
F is the force of air resistance
ρ is the air density (1.22 kg/m^3)
A is the area of the parachute (100 m^2)
v is the velocity of the parcel
Cd is the drag coefficient (1.5)
When the force of air resistance is equal to the weight of the parcel, the parcel will stop accelerating and will reach its terminal velocity. Therefore, we can set the force of air resistance equal to the weight of the parcel:
F = mg
Substituting the values into the equation, we get:
(1/2)ρAv^2Cd = mg
Solving for v, we get:
v = sqrt((2mg)/(ρACd))
Substituting the values into the equation, we get:
v = sqrt((2 x 700 x 9.8)/(1.22 x 100 x 1.5)) = 25.9 m/s
This means that the velocity at which the parcels will hit the ground when they are attached to the parachutes is 25.9 m/s.
Conclusion:
Based on our calculation, the 100 square meter parachutes with a drag coefficient of 1.5 are suitable for dropping 700-kilogram parcels from a plane at a refugee camp. The velocity at which the parcels will hit the ground when they are attached to the parachutes is 25.9 m/s, which is below the maximum velocity of 5 m/s specified by the U.S. Army. However, if the mass of the parcels or the area of the parachutes changes, the velocity at which the parcels hit the ground will also change. Therefore, it is important to recalculate the velocity for different scenarios to ensure the safety of the parcels.
Step-by-step explanation: