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faltersainse [42]

3 years ago

14

A truck is hauling a 300-kg log out of a ditch using a winch attached to the back of the truck. Knowing the winch applies a cons

tant force of 2650 N and the coefficient of kinetic friction between the ground and the log is 0.45, determine the time for the log to reach a speed of 0.5 m/s.

1 answer:

sammy [17]3 years ago

3 0

Answer:

t = 0.113 s

Explanation:

In this exercise we can use Newton's second law

X Axis F - fr = ma

Y Axis N –W = 0

N = W = m g

The force of friction is

fr = μ N

We replace

F - μ m g = m a

a = (F- μ mg) / m

a = (2650 - 0.45 300 9.8) / 300

a = 4,423 m / s2

Now we can use the kinematics expressions, where we assume that the system starts with zero speed

v = v₀ + a t

t = v / a

t = 0.5 / 4.423

t = 0.113 s

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With initial grade, the elevation of PVC is

$E_{PVC}=E_{PVI}+G_1(L/2)\\E_{PVC}=122+1.5%(460/2)\\E_{PVC}=125.45 ft\\$

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$St_{PVC}=St_{PVI}-(L/2)\\St_{PVC}=24000-(230)\\St_{PVC}=237+70\\$

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$St_{low}=St_{PVC}-(x)\\St_{low}=23770+(172.5)\\St_{low}=239+42.5 ft\\$

The elevation is given as

$E_{low}=\frac{G_2-G_1}{2L} x^2+G_1x+E_{PVC}\\E_{low}=\frac{2.5-(-1.5)}{2*460} (1.72)^2+(-1.5)*(1.72)+125.45\\E_{low}=124.16 ft$

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3 years ago

If we have silicon at 300K with 10 microns of p-type doping of 4.48*10^18/cc and 10 microns of n-type doping at 1000 times less

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Answer:

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If gain of the critically damped system is increased, the system will behave as a) Under damped b) Over damped c) Critically dam

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Answer:

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3 years ago

Read 2 more answers