Is -3 a solution to equation 3x -5 = 4+ 2x

A freight train has a mass of [02] kg. The wheels of the locomotive push back on the tracks with a constant net force of 7.50 ×

otez555 [7]

Answer:

t = 300.3 seconds

Explanation:

Given that,

The mass of a freight train, $m=1.01\times 10^7\ kg$

Force applied on the tracks, $F=7.5\times 10^5\ N$

Initial speed, u = 0

Final speed, v = 80 km/h = 22.3 m/s

We need to find the time taken by it to increase the speed of the train from rest.

The force acting on it is given by :

F = ma

or

$F=\dfrac{m(v-u)}{t}\\\\t=\dfrac{m(v-u)}{F}\\\\t=\dfrac{1.01\times 10^7\times (22.3-0)}{7.5\times 10^5}\\\\t=300.3\ s$

So, the required time is 300.3 seconds.

4 0

2 years ago

When the tube is filled with mercury vapor, as in this case, a sharp drop in the collected current is observed when the accelera

Nata [24]

Answer:

The energy absorbed by the atomic electrons in the mercury atom is $7.84 \times 10^{-19}$ J

Explanation:

Given:

Potential $V = 4.9$ V

According to the conservation law,

Loss in kinetic energy = Gain in potential energy

Here, energy absorbed by the atomic electrons is given by,

$E = eV$

Where $e = 1.6 \times 10^{-19} C$ ( charge of electron )

$E = 1.6 \times 10^{-19 } \times 4.9$

$E = 7.84 \times 10^{-19}$ J

Therefore, the energy absorbed by the atomic electrons in the mercury atom is $7.84 \times 10^{-19}$ J

5 0

2 years ago

Let's take two balls, each of radius 0.1 meters and charge them each to 3 microCoulombs. Then, let's put them on a flat surface

salantis [7]

Explanation:

First, we will calculate the electric potential energy of two charges at a distance R as follows.

R = 2r

= $2 \times 0.1 m$

= 0.2 m

where, R = separation between center's of both Q's. Hence, the potential energy will be calculated as follows.

U = $\frac{k \times Q \times Q}{R}$

= $\frac{8.98 \times 10^{9} \times (3 \times 10^{-6} C)^{2}}{0.1}$

= 0.081 J

As, both the charges are coming towards each other with the same energy so there will occur equal sharing of electric potential energy between these two charges.

Therefore, when these charges touch each other then they used to posses maximum kinetic energy, that is, $\frac{U}{2}$ .

Hence, K.E = $\frac{U}{2}$

= $\frac{0.081}{2}$

= 0.0405 J

Now, we will calculate the speed of balls as follows.

V = $\sqrt{\sqrt{\frac{2 \times K.E}{m}}$

= $\sqrt{\sqrt{\frac{2 \times 0.0405}{4 kg}}$

= 0.142 m/s

Therefore, we can conclude that final speed of one of the balls is 0.142 m/s.

6 0

2 years ago

un motor electric efectueaza un lucru mecanic de 864 j in 0.5 min.tensiunea la bornele sale este de 12v si este parcurs de un cu

GrogVix [38]

Answer:

96%

Explanation:

To find the values of the motor efficiency you use the following formula:

$E=\frac{P_o}{P_i}100$

P_o: output power = 864J/0.5min=864J/30s=28.8W

P_i: input power = I*V = (3A)(12V) = 36W

By replacing this values you obtain:

$E=\frac{28.8W}{30W}*100=96\%$

hence, the motor efficiency is about 96%

traslation:

Pentru a găsi valorile eficienței motorului, utilizați următoarea formulă:

P_o: putere de ieșire = 864J / 0.5min = 864J / 30s = 28.8W

P_i: putere de intrare = I * V = (3A) (12V) = 36W

Înlocuind aceste valori obțineți:

prin urmare, eficiența motorului este de aproximativ 96%

3 0

2 years ago

NEED HELP!!! ANSWER THESE 4 QUESTIONS FOR 20 POINTS!!!! PLEASE ANSWER!! I WILL GIVE YOU BRAINEST

MatroZZZ [7]

Answer:

1)A

2)C

3)A

4)C

Pls give brainliest

I ACTUALLY NEED IT!!!

5 0

1 year ago