Question

In: Physics

Assume the density of air is ρ = 1.21 kg/m3. A 75-kg skydiver descending head first...

Assume the density of air is ρ = 1.21 kg/m3. A 75-kg skydiver descending head first without parachute will have an area approximately A = 0.18 m2 and a drag coefficient of approximately C=0.70. (a) What would be the predicted terminal velocity of this person if falling from very high altitude (high enough to generate terminal velocity). (b) how many meters above the ground the airplane must fly in order for this person to generate that terminal velocity at the height of 500 meters above the ground?

Solutions

Expert Solution

(a)

At terminal velocity, the drag force on the skydiver must be equal to the force of gravity the person’s weight). Using the expression for the drag force, we can write

   

  

  

(b) The distance from the ground at which the skydiver jumps out of the airplane can be found using the kinematic equation.

  

  

  

Hence, the airplane must fly at a height of   from the ground in order for the person to generate that terminal velocity.


Related Solutions

An 80 kg skydiver falls through air with a density of 1.15 kg/m3 . Assume that...
An 80 kg skydiver falls through air with a density of 1.15 kg/m3 . Assume that his drag coefficient is C=0.57. When he falls in the spread-eagle position his body presents an area A1=0.94 m2 to the wind, whereas when he dives head first, with arms close to the body and legs together his area is reduced to A2=0.21 m2 . What are the terminal speeds in both cases?
Uncertainty calculation  I want to determine the air density (ρ, in kg/m3) using the following...
Uncertainty calculation  I want to determine the air density (ρ, in kg/m3) using the following equation. p=(1/R)*(P/T) where P : barometric pressure, in Pa T: temperature, in K R: specific gas constant for dry air, 289.7 J/(kg·K) [assume constant has no uncertainty]  I performed a sample-to-sample experiment with 6 repetitions/samples (n = 6). I got following results: P = 96,389 ± 167 Pa T = 311.8 ± 2.93 K  The tags on the sensors show the barometric...
Say the density of air is 1.23 kg/m3 and the density of helium is 0.164 kg/m3...
Say the density of air is 1.23 kg/m3 and the density of helium is 0.164 kg/m3 when both are at STP. Let's model a balloon as a sphere of radius 0.12 m, with mass 2 g. 1) What is the mass of the helium that would fill a single balloon? 2) What is the buoyant force on a single balloon? 3) What is the net force on a single balloon? 4) If we attach 0.5 m of string (properties: 800...
A 1-mm diameter sphere (density=7900 kg/m3) is dropped into a tank of oil (density=900 kg/m3). The...
A 1-mm diameter sphere (density=7900 kg/m3) is dropped into a tank of oil (density=900 kg/m3). The sphere develops a terminal speed of 0.25 cm/s, what is the oil's viscosity? You may assume a small Reynolds number. Show your work.
A 8.9 kg rock whose density is 4500 kg/m3 is suspended by a string such that...
A 8.9 kg rock whose density is 4500 kg/m3 is suspended by a string such that half of the rock's volume is under water. What is the tension in the string?
3) A piece of metal with a mass of 3.8 kg and density of 1808 kg/m3...
3) A piece of metal with a mass of 3.8 kg and density of 1808 kg/m3 is suspended from a string and then completely immersed in a container of water. The density of water is 1000 kg/m3 . (a) Determine the volume of the piece of metal. (b) Determine the tension in the string after the metal is immersed in the container of water. SHOW ALL WORK AND FORMULAS! THANKS!
The figure shows a spherical shell with uniform volume charge density ρ = 2.18 nC/m3, inner...
The figure shows a spherical shell with uniform volume charge density ρ = 2.18 nC/m3, inner radius a = 9.30 cm, and outer radius b = 2.6a. What is the magnitude of the electric field at radial distances (a) r = 0; (b) r = a/2.00, (c) r = a, (d) r = 1.50a, (e) r = b, and (f) r = 3.00b?
The figure shows a spherical shell with uniform volume charge density ρ = 1.88 nC/m3, inner...
The figure shows a spherical shell with uniform volume charge density ρ = 1.88 nC/m3, inner radius a = 9.70 cm, and outer radius b = 3.4a. What is the magnitude of the electric field at radial distances (a) r = 0; (b) r = a/2.00, (c) r = a, (d) r = 1.50a, (e) r = b, and (f) r = 3.00b?
3.1. Oil with (ρ = 788 kg/m3 and ν=0.00067 m2 is removed to the atmosphere through...
3.1. Oil with (ρ = 788 kg/m3 and ν=0.00067 m2 is removed to the atmosphere through a pipe, 7mm diameter, and 37m long. The pipe is located 3.5m from the top of the oil. If the pipe is build using smooth stainless steel, find the flow rate of the oil and the condition of the flow. 3.2. A water tank is located at the top of the roof with 20°C of water that will be used for showers. The tank...
A trough is filled with a liquid of density 850 kg/m3. The ends of the trough...
A trough is filled with a liquid of density 850 kg/m3. The ends of the trough are equilateral triangles with sides 8 m long and vertex at the bottom. Find the hydrostatic force on one end of the trough. (Use 9.8 m/s2 for the acceleration due to gravity.)
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT