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3 years ago

Not including thinking distance, lawful brakes must stop a car at 20 miles per hour within how many feet?

Physics

2 answers:

Svetradugi [14.3K]3 years ago

5 0

Answer:

B. 25 feet

Explanation:

In most cities in US, passenger car brakes must stop a car moving at 20 miles per hour at 25 feet.

Therefore, the correct option is "B" 25 feet

Sholpan [36]3 years ago

4 0

Answer:

Option-(B): The ideal distance that a lawful brakes must stop a car traveling at a speed of 20 miles per hour is about 20 feet.

Explanation:

If are often asked not speed too much while traveling, because some times we are not able to control the machine that we are driving. And the government or the concerned authorities are directed to develop a system to prevent any damage to any person on the road. The road roads bumps are thus made to prevent any road accidents which can some times be very fatal to multiple individuals.

But, we have the scientific formulas to know about the situations. As we have the equation.

Brakes or stoppage distance= (Speed of the car)²/ speed of the same car,

Now if we insert the values then we get that:

Stoppage distance= 20 feet. ⇒ Answer.

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Is it possible to produce a continuous and oriented aramid fiber–epoxy matrix composite having longitudinalandtransverse moduli

Masja [62]

Answer:

Not possible

Explanation:

$E_{cl}$ = longitudinal modulus of elasticity = 35 Gpa

$E_{ct}$ = transverse modulus of elasticity = 5.17 Gpa

$E_m$ = Epoxy modulus of elasticity = 3.4 Gpa

$V_{\rho l}$ = Volume fraction of fibre (longitudinal)

$V_{\rho t}$ = Volume fraction of fibre (transvers)

$E_f$ = Modulus of elasticity of aramid fibers = 131 Gpa

Longitudinal modulus of elasticity is given by

$E_{cl}=E_m(1-V_{\rho l})+E_fV_{\rho l}\\\Rightarrow 35=3.4(1-V_{\rho l})+131V_{\rho l}\\\Rightarrow 35=3.4-3.4V_{\rho l}+131V_{\rho l}\\\Rightarrow V_{\rho l}=\frac{35-3.4}{131-3.4}\\\Rightarrow V_{\rho l}=0.24764$

Transverse modulus of elasticity is given by

$E_{ct}=\frac{E_mE_f}{(1-V_{\rho t})E_f+V_{\rho t}E_m}\\\Rightarrow 5.17=\frac{3.4\times 131}{(1-V_{\rho t})131+V_{\rho t}3.4}\\\Rightarrow \frac{3.4\times 131}{5.17}-131=-127.6V_{\rho t}\\\Rightarrow V_{\rho t}=\frac{\frac{3.4\times 131}{5.17}-131}{-127.6}\\\Rightarrow V_{\rho t}=0.35148$

$V_{\rho l}\neq V_{\rho t}$

Hence, it is not possible to produce a continuous and oriented aramid fiber.

5 0

3 years ago

50 POINTS!!!!!!!! In a GUT (Grand Unified Theory), what is "unified"?

melomori [17]

Subatomic particles

Explanation:

Grand unification theory or GUT is a model that tries to describe the universe.

7 0

3 years ago

Which type of graph is best suited to show the breakdown of how this teacher weights each category ?

MArishka [77]

Answer:

pie graph?

Explanation:

6 0

4 years ago

Read 2 more answers

The diagram below shows the velocity vectors for two cars that are moving relative to each other.

scoundrel [369]

Answer:

The answer is " $5 \ \frac{m}{s} \ west$ "

Explanation:

$\to \vec{V_1} = (25 \frac{m}{s}) (\hat{-i})\\\\\to \vec{V_2} = (20 \frac{m}{s}) (\hat{-i})\\\\$

velocity of car | respect to car :

$\to \vec{V_{12}} = \vec{V_1} - \vec{V_2}\\\\$

$=\vec{-25} \hat{i}+ \vec{20} \hat{i}\\\\= 5 \ \frac{m}{s} \ west$

7 0

3 years ago

An object at 27°C has its temperature increased to 37°C.

Firlakuza [10]

Answer:

b. 14

Explanation:

$T_{i}$ = Initial temperature = 27 °C = 27 + 273 = 300 K

$T_{f}$ = Final temperature = 37 °C = 37 + 273 = 310 K

$P_{i}$ = Initial Power radiated by the object

$P_{f}$ = Final Power radiated by the object

We know that the power radiated is directly proportional to fourth power of the temperature. hence

$\frac{P_{f}}{P_{i}} = \frac{T_{f}^{4} }{T_{i}^{4} }\\\frac{P_{f}}{P_{i}} = \frac{(310)^{4} }{(300)^{4} }\\\frac{P_{f}}{P_{i}} = 1.14\\P_{f} = (1.14) P_{i}$

Percentage increase in power is given as

$\frac{(P_{f} - P_{i})\times100}{P_{i}} \\\frac{((1.14) P_{i} - P_{i})\times100}{P_{i}} \\14$

3 0

4 years ago