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AnnyKZ [126]
3 years ago
13

An engineer in a locomotive sees a car stuck on the track at a railroad crossing in front of the train . When the engineer first

sees the car, the locomotive is 110 m from the crossing and its speed is 21 m/s . If the engineer's reaction time is 0.6 s, what should be the magnitude of the minimum de celeration to avoid an accident ? Answer in units of m/s^ 2
Physics
1 answer:
8_murik_8 [283]3 years ago
4 0

Answer:

Explanation:

distance traveled during reaction time

d = vt = 21(0.6) = 12.6 m

distance remaining 110 - 12.6 = 97.4 m

Assuming we want zero speed in 97.4 m using constant acceleration.

a = (0² - 21²) / 2(97.4) = - 2.2638603...

the negative value indicates acceleration opposes initial velocity.

magnitude is

a = 2.3 m/s²

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bezimeni [28]

Answer:

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Explanation:

4 0
2 years ago
1. Apply a constant force of 50 N directed to the right of the 50 kg Box. (2 pts)
kotegsom [21]

As the box is moving with a constant velocity, the two forces acting on the box are canceling each other.

Then   friction force = 80 Newtons              but in the opposite direction.

Friction force =  Mu  * Normal force exerted by ground  =  Mu * weight of box

So we find Mu.

Mu = coefficient of friction between box and horizontal surface

          = Force of friction / weight  =  80 / 50 * 9.81 = 0.163

When an identical box is placed on top, the force of friction is

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7 0
3 years ago
Suppose the gas resulting from the sublimation of 1.00 g carbon dioxide is collected over water at 25.0◦c into a 1.00 l containe
AlexFokin [52]

Answer:

0.56 atm

Explanation:

First of all, we need to find the number of moles of the gas.

We know that

m = 1.00 g is the mass of the gas

Mm=44.0 g/mol is the molar mass of the carbon dioxide

So, the number of moles of the gas is

n=\frac{m}{M_m}=\frac{1.00 g}{44.0 g/mol}=0.023 mol

Now we can find the pressure of the gas by using the ideal gas equation:

pV=nRT

where

p is the pressure

V=1.00 L = 0.001 m^3 is the volume

n = 0.023 mol is the number of moles

R=8.314 J/mol K is the gas constant

T=25.0^{\circ}+273=298 K is the temperature of the gas

Solving the equation for p, we find

p=\frac{nRT}{V}=\frac{(0.023 mol)(8.314 J/mol K)(298 K)}{0.001 m^3}=5.7 \cdot 10^4 Pa

And since we have

1 atm = 1.01\cdot 10^5 Pa

the pressure in atmospheres is

p=\frac{5.7\cdot 10^4 Pa}{1.01\cdot 10^5 Pa/atm}=0.56 atm

5 0
3 years ago
The human body is a system of systems that rely on each other to sustain a life. Explain how.
Misha Larkins [42]
The human body is connected in every way. All the organs are connected and help each other be alive. For example, the veins are connected to the heart, which help it by pumping blood and oxygen. If they weren’t there, the heart wouldn’t be able to sustain a life.
I really hope this gave you and ideas and helped you in some way:)
4 0
3 years ago
Help with these questions please?
egoroff_w [7]

Answer:

5. dispersion

6. 49.8°

Explanation:

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___

6. n = 1.31 is the ratio of the sine of the angle of refraction to the sine of the angle of incidence (for light passing to a medium of n = 1). When the angle of refraction is 90°, the angle of incidence is the "critical angle." So, ...

sin(90°)/sin(critical) = 1.31

critical angle = arcsin(1/1.31) ≈ 49.8°

8 0
3 years ago
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