CONSIDER A TRAIN WHICH CAN ACCELERATION OF 20CM/SEC AND SLOW DOWN WITH ACCELERATION OF 100 CM/SEC FIND THE MINIMUM TIME FOR TRAIN TO TRAVEL BETWEEN THE STATIONS 2.7 KM PER A PART

Answers

Answer 1
Answer: The train accelerates at the rate of 20 for some time, until it's just exactly
time to put on the brakes, decelerate at the rate of 100, and come to a
screeching stop after a total distance of exactly 2.7 km.

The speed it reaches while accelerating is exactly the speed it starts decelerating from.

Speed reached while accelerating = (acceleration-1) (Time-1) = .2 time-1

Speed started from to slow down = (acceleration-2) (Time-2) = 1 time-2  

The speeds are equal.
.2 time-1 = 1 time-2
time-1 = 5 x time-2

It spends 5 times as long speeding up as it spends slowing down.

The distance it covers speeding up = 1/2 A (5T)-squared
= 0.1 x 25 T-squared = 2.5 T-squared.

The distance it covers slowing down = 1/2 A (T-squared)
= 0.5 T-squared.

Total distance = 2,700 meters.
(2.5 + .5) T-squared = 2,700
T-squared = 2700/3 = 900

T = 30 seconds

The train speeds up for 150 seconds, reaching a speed of 30 meters per sec
and covering 2,250 meters. 
It then slows down for 30 seconds, covering 450 meters.

Total time = 180 sec = 3 minutes, minimum.

Observation:
This solution is worth more than 5 points.
Answer 2
Answer: This can be done by hit and trial easily.

Considering train accelerate for 13000s and deaccelerate for 1000s
so total distance covered is = 20cm/s * 13000s + 100cm/s*100s
= (260000 + 10000 )cm
= 270000cm
= 2.7km

So total time taken is - 13100 seconds


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an input force of 50 Newtons is applied through a distance of 10 meters to machine with mechanical advantage of 3. If the work output for the machine is 450 newton x meters and this work is applied through a distnace of 3 meters, what is the output force of the machine

Answers

The output of the machine is

                                      (output work) =  (output force) x (distance)

                                        450 N-m      =  (output force) x (3 meters)

Divide each side
by  3 meters:                Output force = (450 N-m) / (3 m)

                                                           =    150 newtons .

With all the information given about the output work, we don't need
to know anything about the input work, or even the fact that we're
dealing with a machine.

It's comforting, though, to look back and notice that the output work
(450 N-m) is not more than the input work (500 N-m).  So everything
is nice and hunky-dory.
___________________________________

Well, my goodness !
I didn't even need to go through all of that.

Given:

-- The input force to the machine is 50 newtons.

-- The mechanical advantage of the machine is 3 .

That right there tells us that

-- The output force of the machine is 150 newtons.

We don't need any of the other given information.

What is a dwarf planet?

Answers

A dwarf planet is a small celestial body resembling a planet, but lacks necessary things to be a planet
Hey, Sverlnexlcasatyr!
A dwarf planet looks like a planet, but is missing things to become a planet. For example, Pluto is now a dwarf planet. 
I hope this helps;)

Suppose you decide to cut the wire into two pieces (not necessarily the same length) to shape into two circles. Write a function A ( x ) which models the total area of the two circles in terms of x , the length of one of the pieces of wire. (It may be helpful to use for a circle A = πr 2 and C = 2 πr ). Then find the length x that will minimize the total area.

Answers

Answer:

2\pi r(r+rx)

Explanation:

Let the area of one circular side be given by the formula : A_(1)  = \pi r^(2)

However, the wire is a solid cylinder, then it means that the total area is 2 × \pi r^(2) =2\pi r^(2)

However, there is the surface area to consider. This is the curved area of the wire. This is given as:

A_(2)  = lb

The length is x.

The breadth is calculated as follows  - the length of the circle = \pi D = 2\pi r

Then the area = lb

                        =2\pi rx

Therefore, the total area is given as A_(1)  + A_(2)

                       = 2\pi r^(2) + 2\pi rx\n 2\pi r(r+rx)

1380 kg car is moving due east with an initial speed of 27.0 m/s. after 8.00 s the car had showd dwn to 17.0 m/s. find the magnitude and direction of the net force that produces the deceleration

Answers

Answer:

magnitude of force is 1725 N

direction is opposite to the direction of car moving  i.e west

Explanation:

Given data

car mass = 1380 kg

speed = 27.0 m/s

time = 8 s

speed = 17 m/s

to find out

magnitude and direction of the net force

solution

we find here first acceleration thats formula is

a = v(initial) - v(final) / time

a =27 - 17 / 8

acceleration = 1.25 m/s

so force is = ma

force is = 1380 ( 1.25)

force = 1725 N

so magnitude of force is 1725 N

and this is here direction is opposite to the direction of car moving  i.e west

Final answer:

The net force that leads to the deceleration of the 1380 kg car from 27.0 m/s to 17.0 m/s over 8.00 seconds has a magnitude of 1725 N and is directed towards the west.

Explanation:

To solve for the magnitude and direction of the net force that produces the deceleration in the car, you first need to calculate the acceleration and then use it to find the net force using the formula f = m * a. The acceleration here represents a deceleration because the speed is decreasing.

Acceleration can be found using the formula a = (v_f - v_i) / t. Here, v_i is the initial speed (27.0 m/s), v_f is the final speed (17.0 m/s), and t is the time interval (8.00 s). This gives you a = (17.0 m/s - 27.0 m/s) / 8.00 s = -1.25 m/s^2. The negative sign represents deceleration.

Now, apply this deceleration to the formula for force, f = m * a. Here, m is the mass of the car (1380 kg) and a is the value we computed (-1.25 m/s^2). So, f = 1380 kg * -1.25 m/s^2 = -1725 N. The negative sign indicates that the force is in the direction opposite to the initial motion of the car. Therefore, the magnitude of the net force is 1725 N, and the direction is towards the west or opposite to the car's original path.

Learn more about Net Force Calculation here:

brainly.com/question/14361879

#SPJ3

What influences the Earth's tides and climate?A. Moon
B. Mars
C. the Milky Way
D. Venus

Answers

The moon influences the Earth's tides.

None of the items on this list of choices influences the seasons.
the moon influences the tides and climate

What happens when an organism is removed from a food chain?

Answers

The food chain will collapse with the decreases and increases of other organisms caused by the removed organism.

There will be far-reaching effects. If for example, the producer is removed, the consequences could be dire.