To solve this problem, it is necessary to use the concepts related to the Force given in Newton's second law as well as the use of the kinematic equations of movement description. For this case I specifically use the acceleration as a function of speed and time.

Finally, we will describe the calculation of stress, as the Force produced on unit area.

By definition we know that the Force can be expressed as

F= ma

Where,

m= mass

a = Acceleration

The acceleration described as a function of speed is given by

$a = \frac{\Delta v}{\Delta t}$

Where,

$\Delta v =$ Change in velocity

$\Delta t =$ Change in time

The expression to find the stress can be defined as

$\sigma=\frac{F}{A}$

Where,

F = Force

A = Cross-sectional Area

Our values are given as

$v= 80km/h\\t=5.8*10^3s\\m = 3kg \\A = 2.3*10^{-4}m^2$

Replacing at the values we have that the acceleration is

$a = \frac{\Delta v}{\Delta t}$

$a = \frac{80km/h(\frac{1h}{3600s})(\frac{1000m}{1km})}{5.8*10^3}$

$a = 3831.41m/s^2$

Therefore the force expected is

$F = ma\\F = 3*3831.41m/s^2 \\F = 11494.25N$

Finally the stress would be

$\sigma = \frac{F}{A}$

$\sigma = \frac{11494.25N}{2.3*10^{-4}}$

$\sigma = 49.97*10^6 Pa = 49.97Mpa$

Therefore the compressional stress that the arm withstands during the crash is 49.97Mpa

8 0

3 years ago

The photograph shows a kettle made of the element copper. Which statement describes a chemical property of copper?

Aleks04 [339]

A copper forms a patina when it interacts with air

7 0

2 years ago

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Th e heat capacity of air is much smaller than that of water, and relatively modest amounts of heat are needed to change its tem

Darina [25.2K]

Answer:

Q=1005 J

t= 0.67 sec

Explanation:

Lets take condition of room is 1 atm and 25°C.

Heat capacity ,c = 21 J /K.mol

If we assume that air is ideal gas that

P V = n R T

$V= 5.5\times 6.5\times 3\ m^3$

$V=107.25\ m^3$

$V=107.25\times 1000 L$

V= 107250 L

At STP number of moles given as

$n=\dfrac{V}{V_{at\ S.T.P.}}$

V=22.4 L at S.T.P.

$n=\dfrac{107250}{22.4}\ moles$

n=4787.94 moles

n= 4.784 Kmoles

So heat required to raise 10°C temperature

Q = n x c x ΔT

Q = 4.78794 x 21 x 10

Q=1004.64 J

Time t

t= Q/P

P= 1.5 KW

t = 1.004.64 /1.5

t= 0.66 sec

4 0

4 years ago

Read 2 more answers

Microorganisms that occur or have adapted to live in a specific environment are called a. fomites. b. droplets. c. pathogen. d.

tino4ka555 [31]

The microorganism that occurs or has adapted to live in a specific environment is called D. Flora. Normal Flora or Flora lives inside the body without harming the person. They are mostly found in the large intestine. I hope you find this helpful.

5 0

4 years ago