Find the time taken if the speed of a train increased rom 72km/h to 90km/h for 234km

Direct current (DC) is the flow of electric charge in only one direction. It is the steady state of a constant-voltage circuit. Most well-known applications, however, use a time-varying voltage source. Alternating current (AC) is the flow of electric charge that periodically reverses direction.

Answer:

2.82 m/s²

Explanation:

[tex]v = u + at \\ 24 = 0 + a(8.5) \\ a = 2.82 \: ms {}^{ - 2} [/tex]

The acceleration of a motorcycle is 2.82 m/s^2.

Acceleration is the rate at which speed and direction of velocity vary over time. A point or object going straight ahead is accelerated when it accelerates or decelerates.

Even if the speed is constant, motion on a circle accelerates because the direction is always shifting. Both effects contribute to the acceleration for all other motions.

Given that:

Initial velocity of the motor cycle: u = 0 m/s.

Final velocity of the motorcycle = 24 meter/second.

Time taken to reach this velocity = 8.5 second.

Hence, acceleration of the motor cycle = change in velocity/time interval

= ( final velocity - initial velocity)/time interval

= ( 24 m/s  - 0 m/s)/8.5 s

= 2.82 m/s^2.

Its acceleration is 2.82 m/s^2.

Learn more about acceleration here:

brainly.com/question/12550364

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Answer:

2 Hz.

Explanation:

Frequency is simply defined as the number of appearances of a periodic event occurring per time. It is usually measured in cycles/second.

Now, in this question, we are told that there are 2 cycles for each second.

Thus, we can say that the frequency is 2 cycles/1 s = 2 Hz.

Question:

What do you think will happen to the people in the airplane if their location is unknown?

My opinion:

I mean what are the circumstances? Is it just a rogue pilot that takes a random plane with all the passengers Hostage or is It bad whether an they lose connection to the airport? I Mean either way, If I was on a plane being held hostage, or the plane crashing, I Would be a in a panic type state of mind. I Would be worried about what will happen when the plane crashes, I would worry about my friends or family that is aboard the plane with me, I Would be scared for my life because I Don't know if i would make it out alive.

Also:

How would they know their location is unknown wouldn't the Pilot be the only one to know exactly where there with their navigating system, But then again there was this time I headed to Florida an They had mini tv's on the seats of each chair, where you could: Watch movies, listen to music, an Also see exactly where you are in the world. It was really amazing actually.

Answer:

F2 = 900 lbs

Explanation:

From pascal principle;

F1/A1 = F2/A2

Force on cylinder at left; F1 = 100 lbs

Diameter of cylinder at left; d1 = 2 inches

Diameter of cylinder at right; d2 = 6 inches

Formula for area of top of cylinder = πr²

Thus;

Area of top of left cylinder; A = π × 2² = 4π

Area of top of right cylinder; A = π × 6² = 36π

Thus;

100/4π = F2/36π

F2 = (36π × 100)/4π

F2 = 900 lbs

Answer:

I = 0.2 A

Explanation:

Lamp is rated at 300 mA

I_lamp = 300 mA = 0.3 A

Voltage is; V = 3V

Thus; Resistance is given by;

R = V/I

R = 3/0.3

R = 10 ohms

Now, since the ammeter of 5 ohms is connected in series with the lamp. Thus equivalent resistance;

R_eq = 10 + 5

R_eq = 15 ohms

Ammeter current will be;

I = V/R_eq

I = 3/15

I = 0.2 A

Explanation:

Given that,

The voltages across them are 40,50 and 60 volts respectively, and the charge on each condenser is 6×10⁻⁸ C.

(a) Capacitance of capacitor 1,

[tex]C_1=\dfrac{Q}{V_1}\\\\C_1=\dfrac{6\times 10^{-8}}{40}\\\\C_1=1.5\times 10^{-9}\ F\\\\C_1=1.5\ nF[/tex]

Capacitance of capacitor 2,

[tex]C_2=\dfrac{Q}{V_2}\\\\C_2=\dfrac{6\times 10^{-8}}{50}\\\\C_2=1.2\times 10^{-9}\ F\\\\C_2=1.2\ nF[/tex]

Capacitance of capacitor 3,

[tex]C_3=\dfrac{Q}{V_3}\\\\C_3=\dfrac{6\times 10^{-8}}{60}\\\\C_3=1\times 10^{-9}\ F\\\\C_3=1\ nF[/tex]

(b) The equivalent capacitance in series combination is :

[tex]\dfrac{1}{C}=\dfrac{1}{C_1}+\dfrac{1}{C_2}+\dfrac{1}{C_3}\\\\\dfrac{1}{C}=\dfrac{1}{1.5}+\dfrac{1}{1.2}+\dfrac{1}{1}\\\\C=0.4\ nF[/tex]

Hence, this is the required solution.

Answer:

The package should be dropped 244.7 meters before the target

Explanation:

We need to find how long the package will take to hit the ground then solve for position.

y=0

-4.9t^2=-3000

t= sqrt (3000/4.9)

t= 24.74 seconds.

x= 247.4 meters.

Answer:

3420.39 N

Explanation:

Applying,

Fd = 1/2(mv²-mu²)................. Equation 1

Where F = force on the bumber, d = distance, m = mass of the car, v = final velocity, u = initial velocity.

make F the subject of the equation

F = (mv²-mu²)/2d............... Equation 2

From the question,

Given: m = 890 kg, v = 0 m/s (to rest), u = 1.4 m/s, d = 0.255 m

Substitute these values into equation 2

F = [(890×0²)-(890×1.4²)]/(2×0.255)

F = -1744.4/0.51

F = -3420.39 N

The negative sign denotes that the force in opposite direction to the motion of the car.

Answer:

the car’s final displacement is 60 m

Explanation:

Given;

initail velocity of the car, u = 0

acceleration of the car, a = 0.8 m/s²

time of motion, t = 10 s

The first displacement of the car:

[tex]x_1 = ut + \frac{1}{2} at^2\\\\x_1 = 0 + \frac{1}{2} (0.8)(10)^2\\\\x_1 = 40 \ m[/tex]

The second displacement of the car;

acceleration, a = 0.4 m/s²,   time of motion, t = 10 s

[tex]x_2 = ut + \frac{1}{2} at^2\\\\x_2 = 0 + \frac{1}{2} (0.4)(10)^2\\\\x_2 = 20 \ m[/tex]

The final displacement of the car;

x = x₁  +  x₂

x = 40 m  +  20 m

x = 60 m

Therefore, the car’s final displacement is 60 m

Answer:

I = sum m *r^2    where m represents the (small) individual masses and r is the distance of that mass from center of rotation

Note:  sum m = M

For the hoop given all masses are at a distance RRR from the center of rotation

I = MMM * RRR^2

Answer: prevent excitation light from reaching the detector

Explanation:

A fluorometer refers to the device that's used in the measurement of parameters that are of visible spectrum fluorescence. They also prevent excitation light from reaching the detector.

These parameters are used in the identification of the amount and presence of molecules in a medium.

Answer:

Explanation:

Assuming the squirrel is jumping off the ground, here's what we know but don't really know...

v₀ = 4.0 at 50.0°

So that's not really the velocity we are looking for. We are dealing with a max height problem, which is a y-dimension thing. Therefore, we need the squirrel's upward velocity, which is NOT 4.0 m/s. We find it in the following way:

[tex]v_{0y}=4.0sin(50.0)[/tex] which gives us that the upward velocity is

v₀ = 3.1 m/s

Moving on here's what we also know:

a = -9.8 m/s/s and

v = 0

Remember that at the very top of the parabolic path, the final velocity is 0. In order to find the max height of the squirrel, we need to know how long it took him to get there. We are using 2 of our 3 one-dimensional equations in this problem. To find time:

v = v₀ + at and filling in:

0 = 3.1 - 9.8t and

-3.1 = -9.8t so

t = .32 seconds.

Now that we know how long it took him to get to the max height, we use that in our next one-dimensional equation:

Δx = [tex]v_0t+\frac{1}{2}at^2[/tex] and filling in:

Δx = [tex]3.1(.32)+\frac{1}{2}(-9.8)(.32)^2[/tex] and using the rules for adding and subtracting sig fig's correctly, we can begin to simplify this:

Δx = .99 - .50 so

Δx = .49 meters

Answer:

the statement is TRUE

Explanation:

Most lenses are made of glass that has a strong absorption below 400 nm,

Only special evaporation lenses are made of quartz and fused silica which has a high absorption below 200 nm.

therefore the statement is TRUE

Answer:

C: the process by which stars create the heavier elements

Explanation:

Stellar nucleosynthesis is defined as the process of nuclear fusion by which heavier elements are formed within stars by from the combination of protons and neutrons gotten from the nuclei of lighter elements.

Looking at the options, the correct one is Option C

Answer:

dependent: the outcome of the experience

independent variable: everything literaly.

Independent is where you change some variables and see the result

Dependent is literaly the result, or the outcome dependent on the exprience.

Explanation:

I got u.

Answer:

Time, t = 2 seconds

Explanation:

Given the following data;

Mass, m = 50 kg

Initial velocity, u = 0 m/s (since it's starting from rest).

Final velocity, v = 8 m/s

Force, F = 200 N

To find the time, we would use the following formula;

[tex] F = \frac {m(v - u)}{t} [/tex]

Making time, t the subject of formula, we have;

[tex] t = \frac {m(v - u)}{F} [/tex]

Substituting into the formula, we have;

[tex] t = \frac {50(8 - 0)}{200} [/tex]

[tex] t = \frac {50*(8)}{200} [/tex]

[tex] t = \frac {400}{200} [/tex]

Time, t = 2 seconds

Answer:

im pretty sure it should be 50.0

Answer:

Part A

a)  F = -16x + 4,  b)  x = 0.25 m, c) STABLE

Explanation:

Part A

a) Potential energy and force are related

          F = [tex]- \frac{dU}{dx}[/tex]- dU / dx

          F = - (8 2x -4)

          F = -16x + 4

b) The object is in equilibrium when the forces are zero

          0 = -16x + 4

          x = 4/16

          x = 0.25 m

c) An equilibrium position is called stable if with a small change in position, the forces make it return to the initial position, in case the forces make it move away it is called unstable.

In this case there is only one equilibrium point

by changing the position a bit

           x ’= x + Δx

we substitute

          F ’= - 16 x’ + 4

          F ’= - 16 (x + Δx) + 4

          F ’= (-16x +4) - 16 Δx

at equilibrium position F = 0

          F ’= 0 - 16 Δx

we can see that the body returns to the equilibrium position, therefore it is STABLE

PART B

This is an exercise in body collisions, let's define the system formed by the two bodies in such a way that the forces during the collisions are internal and the moment is conserved

initial instant. Before the shock

        p₀ = m v

final instant. After the crash

        p_f = (m + M) v_f

We have two possibilities: an elastic collision in which the bodies separate, each one maintaining its plus, and an INELASTIC collision where the neutron is absorbed by the nucleus and the final mass is M '= m + M, in this case they indicate that the collision is elastic

          p₀ = pf

          mv = mv ’+ M v_f

in the case of the elastic collision, the kinetic energy is conserved

        K₀ = K_f

        ½ m v² = ½ m v’² + ½ M v_f²

we write the system of equations

        mv = mv ’+ M v_f (1)

         m (v² -v'²) = M v_f ²

         m (v - v ’) = M v_f

         m (v-v ’) (v + v’) = M v_f

        v + v ’= v_f

we substitute in equation 1 and solve

         v ’=[tex]\frac{m -M }{m+M } \ vo[/tex]

         v_f = [tex]\frac{2m}{m+M} \ v_o[/tex]

the mechanical energy of the neutron is

  initial

          Em₀ = K = ½ m v²

final moment

          Em_f = K + U = ½ m v_f ² + U

U is the energy lost in the collision

total energy is conserved

          Em₀ = Em_f

          ½ m v² = ½ m v_f ² + U

         U = ½ m (v² -v_f ²)

         U = ½ m [v² - ( [tex]\frac{m-M}{m+M}[/tex]  v)² ]

       U = ½ m v² [1- ( [tex]\frac{m-M}{m+M}[/tex] )² ]

       U = ½ m v2 [ [tex]\frac{2M}{m+M}[/tex]]

       U = [tex]\frac{2 mM}{m +M } \ v^2[/tex]

Let's do the same calculations for the nucleus

initial     Em₀ = 0

final        Em_f = K + U = ½ M v_f ² + U

            Em₀ = Em_f

            0 = K + U

            U = -K

            U = - ½ M v_f ²

            U = - ½ M [ [tex]\frac{2m}{m+M} \ v[/tex] ]²

            U = [tex]\frac{2 m M }{m+M} \ v^2[/tex]  

We can see that we obtain the same result, that is, the potential energy lost by the neutron is equal to the potential energy gained by the nucleus.

b) the fraction of energy lost

          f = U / Em₀

          f = 4 m M / m + M        

c) let's calculate the fraction of energy lost in a collision

          m = 1.67 10⁻²⁷ kg

          M = 12 1.67 10⁻²⁷= 20 10⁻²⁷ kg

         f = 4 1.6 20 / (1.6+ 20)    10⁻²⁷

         f = 5.92 10⁻²⁷ J

the energy of a fast neutron is greater than 1 eV

         Eo = 1 eV (1.67 10⁻¹⁹ J / 1eV) = 1.67 10⁻¹⁹ J

Let's use a direct portion rule if in a collision f loses in how many collisions it loses 0.95Eo

         #_collisions = 0.95 Eo / f

         #_collisions = 0.95 1.67 10⁻¹⁹ / 5.92 10⁻²⁷

         #_collisions = 2.7 10⁷ collisions

Answer:

theory

Explanation:

took the quiz

Answer:

S = 1/2 g t^2      where t is the time to fall 1.2 m

t = (2 S / g)^1/2 = (2 * 1.2 / 9.8) = .495 s

Sy = Vy T = 3 m/sec  * .495  sec = 1.48 m     distance from edge of table

(Rotational speed has no effect since table is smooth)

Answer:

(n) alluvial fan sandbar

Explanation:

Answer:

In coin card experiment smooth card is used so that the card can slide easily from glass

Answer:

Frequency = 24 × 10⁸ Hz

Explanation:

Given the following data;

Speed = 3 × 10⁸ m/s

Wavelength = 0.125 meters

To find the frequency of the electromagnetic wave;

Mathematically, the speed of a wave is given by the formula;

Speed = Wavelength × frequency

Substituting into the formula, we have;

3 × 10⁸ = 0.125 × frequency

Frequency = (3 × 10⁸)/0.125

Frequency = 24 × 10⁸ Hz

Explanation:

Hydraulic Pressure-Control, On-Off Deluge Valve

FP-400Y-5DC

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Answer:

Attenuation

Step By step Explanation:

The decrease in the intensity of light over distance, such as with increasing depth in water, is known as ______.

It is called attenuation.

The decraese in the amplitude of the signals is called attenuation.

Explanation:

when the distance between the 2 objects is halved, the gravitational force between the 2 objects is doubled. when the distance between the 2 objects is doubled then the gravitational force doubles.

Answer:

acceleration = - 150 m/s^2

distance = 9 miles.

Explanation:

initial speed, u = 60 mph

time, t = 12minutes = 0.2 hour

final speed, v = 30 mph

Let the acceleration is a and the distance is s.

By the first equation of motion

v = u + at

30 = 60 + a x 0.2

a = - 150 m/s^2

Let the distance is s.

Use third equation of motion is

[tex]v^2 = u^2 + 2 a s \\\\30^2 = 60^2 + 2 \times 150\times s\\\\s = 9 miles[/tex]