Question 6 of 10

A 52 kg and a 95 kg skydiver jump from an airplane at an altitude of 4750 m, both falling in the pike position. Assume all value

Scilla [17]

Answer: 52 kg skydiver: 9.09 m/s and 522.55 s

95 kg skydiver: 12.3 m/s and 386.2 s

Explanation: Drag Force is an opposite force when an object is moving in a fluid.

For skydivers, when falling through the air, the forces acting on it are gravitational and drag forces. At a certain point, drag force equals gravitational force, which is constant on any part of the planet, producing a net force that is zero. Since there is no net force, there is no acceleration and, consequently, velocity is constant. When that happens, the person reached the Terminal Velocity.

Drag Force and Velocity are proportional to the squared speed. So, terminal velocity is given by:

$F_{G}=F_{D}$

$mg=\frac{1}{2}C \rho Av_{T}^{2}$

$v_{T}=\sqrt{\frac{2mg}{\rho CA} }$

where

m is mass in kg

g is acceleration due to gravitational force in m/s²

ρ is density of the fluid in kg/m³

C is drag coefficient

A is area of the object in the fluid in m²

Calculating:

The 52kg skydiver has terminal velocity of:

$v_{T}=\sqrt{\frac{2(52)(9.8)}{(1.21)(0.7)(0.14)} }$

$v_{T}=$ 9.09

The 95kg skydiver's terminal velocity is

$v_{T}=\sqrt{\frac{2(95)(9.8)}{(1.21)(0.7)(0.14)} }$

$v_{T}=$ 12.3

The 52 kg and 95kg skydivers' terminal velocity are 9.09m/s and 12.3m/s, respectively.

The time each one will reach the floor will be:

52 kg at 9.09 m/s:

$t=\frac{4750}{9.09}$

t = 522.5

95 kg at 12.3 m/s:

$t=\frac{4750}{12.3}$

t = 386.2

The 52 kg and 95kg skydivers' time to reach the floor are 522.5 s and 386.2 s, respectively.

3 0

3 years ago

A projectile is fired straight upward at 173 m/s. how fast is it moving at the instant it reaches the top of its trajectory?

Fittoniya [83]

The top of the trajectory is the point where it changes from rising to falling. At that exact instant, its vertical speed is zero.

8 0

3 years ago

If this wave has frequency of 15 hz. what is the wavelength of that wave ?

Aneli [31]

Do you have any other information? Like the velocity of the wave?

4 0

3 years ago

How does energy travel in a mechanical wave?

VLD [36.1K]

Answer: in a medium

Explanation:

Mechanical waves require medium to transfer energy. The medium particles vibrate about their fixed position to transfer energy. There is no transport of medium particles.

Example, sound waves are mechanical waves. The sound travels through compression and rarefaction of the medium particles.

7 0

4 years ago

Why is gangue sometimes reprocessed.

VLD [36.1K]

Answer:

To win some of the ore associated with them as they can become more economical to produce.

Explanation:

Sometimes gangues are reprocessed so as to win back some of the ore that are associated with them as they become more economical to produce if the price of the metal goes up.

Gangues are undesired minerals that occurs in association with the desired ore. They are usually treated as wastes in mining.

Often times, gangues can become economical to mine.
Some gangues are not totally wastes, they are just undesired materials associated with the ore.
Under certain economic considerations, they might become economical and augment the ore being processed.
The price of the metal determines if the ore in the gangue should be won.

5 0

3 years ago