Help I need to know if it’s true or false

A horizontal curve of a two-lane undivided highway (12-foot lanes) has a radius of 678 feet to the center line of the roadway. A

OLEGan [10]

Answer:

maximum speed for safe vehicle operation = 55mph

Explanation:

Given data :

radius ( R ) = 678 ft

old building located ( m )= 30 ft

super elevation = 0.06

Determine the maximum speed for safe vehicle operation

firstly calculate the stopping sight distance

m = R ( 1 - cos $\frac{28.655*S}{R}$ ) ---- ( 1 )

R = 678

m ( horizontal sightline ) = 30 ft

back to equation 1

30 = 678 ( 1 - cos (28.655 *s / 678 ) )

( 1 - cos (28.655 *s / 678 ) ) = 30 / 678 = 0.044

cos $\frac{28.65 *s }{678}$ = 1.044

hence ; 28.65 * s = 678 * 0.2956

s = 6.99 ≈ 7 ft

next we will calculate the design speed ( u ) using the formula below

S = 1.47 ut + $\frac{u^2}{30(\frac{a}{3.2} )-G1}$ ---- ( 2 )

t = reaction time, a = vehicle acceleration, G1 = grade percentage

assuming ; t = 2.5 sec , a = 11.2 ft/sec^2, G1 = 0

back to equation 2

6.99 = 1.47 * u * 2.5 + $\frac{u^2}{30[(11.2/32.2)-0 ]}$

3.675 u + 0.0958 u^2 - 6.99 = 0

u ( 3.675 + 0.0958 u ) = 6.99

5 0

3 years ago

Redundancy can be implemented at a number of points throughout the security architecture, such as in _____.

pshichka [43]

Redundancy can be implemented at a number of points throughout the security architecture, such as in firewalls

<h3>What is Network Security?</h3>

This refers to the protection that is given to network systems to prevent access from unauthorised users.

Hence, we can see that Redundancy can be implemented at a number of points throughout the security architecture, such as in firewalls

This is because a firewall protects a network and gives access to users and other cookies and files that are allowed into the network.

Read more about firewall here:

brainly.com/question/13693641

#SPJ1

5 0

2 years ago

The net negative charge flowing through a device varies as q(t) = 2.2 t2 C. Find the current through the device at t = 0, 0.5, a

Leni [432]

Answer:

The current at t= 0 sec, is 0 A

The current at t= 0.5 sec, is 2.2 A

The current at t= 1 sec, is 4.4 A

Explanation:

Given that

q(t) = 2.2 t²

We know that:- the change in the charge w.r.t. time is known as current. So,

$I=\dfrac{dq}{dt}$

q(t) = 2.2 t²

$\dfrac{dq}{dt}= 4.4 t$

I= 4.4 t

1.

t = 0 s :

I = 4.4 x 0 = 0 A

Therefore, the current at t= 0 sec, is 0 A

2 .

t= 0.5 s :

I = 4.4 x 0.5 = 2.2 A

Therefore, the current at t= 0.5 sec, is 2.2 A

3.

t= 1 s

I = 4.4 x 1 =4.4 A

Therefore, the current at t= 1 sec, is 4.4 A

4 0

3 years ago

State whether the following statements are true or false. Provide a brief justification for your answer.

Lena [83]

Answer:

[a] False.

[b]. True

[c]. false.

[d]. true.

[e]. true.

Explanation:

NB: SDOF simply means Simple Degree Of Freedom, that is to say it is a system that can be solved by differential equation such as the second order and the single differential equation.

So, the question asked us to determine if each of the scenario is true or false.

a. Consider a SDOF system with Coulomb damping. When displaced from the equilibrium position and released, the mass may not move at all.

ANSWER: FALSE.

REASON: The mass moved a little bit When displaced from the equilibrium position and released.

b. Consider a SDOF system with an ideal viscous damper. When displaced from the equilibrium position and released, the mass will always undergo oscillatory motion.

ANSWER: TRUE

REASON: for an ideal viscous damper. When displaced from the equilibrium position and released, the mass will always undergo oscillatory motion.

c. The damped natural frequency of a system is always greater than the undamped natural frequency

.

ANSWER: FALSE

REASON: The damped natural frequency of a system is always greater than the undamped natural frequency

d. For an undamped system undergoing a harmonic forcing, the amplitude of the response approaches zero as the forcing frequency becomes very high.

ANSWER: TRUE

REASON: the amplitude of the response approaches zero as the forcing frequency becomes very high for undamped system undergoing a harmonic forcing

e. The amplitude of free response of SDOF system with Coulomb damping decreases

ANSWER: TRUE

REASON: amplitude of free response of SDOF system with Coulomb damping decreases

5 0

3 years ago

Which of the following describes when the trial and error approach to problem solving is most successful?

pickupchik [31]

Answer:

I think

when the problem has numerous possible options.

If wrong correct me pls

Have a great day

I hope it helps

$#Liliflim$

5 0

3 years ago