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Lapatulllka [165]
4 years ago
9

A freight car moves along a frictionless level railroad track at constant speed. The freight car is open on top. A large load of

coal is suddenly dumped into the car. What happens to the speed of the freight car
Physics
1 answer:
Wittaler [7]4 years ago
6 0

Answer:

The speed of the freight car decreases.

Explanation:

According to the law of conservation of momentum indicates that for colliding in an isolated system, the total momentum pre and post collision is same for the two objects this is done because the momentum that one item has lost is same for the momentum that the other received

In the given situation, the freight car travels at constant speed along a frictionless railroad line. The top floor freight car is open. Then a huge load of coal is dumped inside the car.

Therefore the speed of the freight car decreased by applying the law of conservation of momentum i

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While traveling home at dusk, a motorcyclist gets on the highway and increases the combined mass (400 kg
alexdok [17]

The acceleration of one of those bugs is equal to 305mi/s.

<h3>Acceleration calculation</h3>

To calculate the insect's acceleration, the action and reaction force of the impact must be considered.

As the insect will hit the helmet, the force it hits is the same force it receives, so we can make the following expression:

                                          m_m \times a_m = m_b \times a_b

                                        550 \times 0.0027 = 5 \times 10^{-3} \times a_b

<em>Speed ​​has been converted to miles per second</em>

                                          a_b = 305 mi/s

So, the acceleration of one of those bugs is equal to 305mi/s.

Learn more about acceleration calculation: brainly.com/question/390784

8 0
2 years ago
A 4.15-volt battery is connected across a parallel-plate capacitor. Illuminating the plates with ultraviolet light causes electr
FromTheMoon [43]

Answer:

a ) 2.13 X 10⁶ m/s .

b ) 1.28 X 10⁶ m/s

Explanation:

When electrons are repelled by negative plates and attracted by positive plates , it will increase their kinetic energy.

Increase in their energy = 4.15 eV

= 4.5 X 1.6 X 10⁻¹⁹ J

= 6.64 x 10⁻¹⁹ J

Initial kinetic energy

= 1/2 mv²

= 1/2 x 9.1 x 10⁻³¹ x ( 1.76 x 10⁶)²

= 14.09 X 10⁻¹⁹ J

Total energy

= 6.64 x 10⁻¹⁹+14.09 X 10⁻¹⁹

= 20.73 x 10⁻¹⁹

If V be the increased velocity

1/2 m V² = 20.73 X 10⁻¹⁹

.5 X 9.1 X 10⁻³¹ V² = 20.73 X 10⁻¹⁹

V = 2.13 X 10⁶ m/s .

b ) When electrons are released from positive plate , their speed are reduced because of attraction between electrons and positively charge plates.

Initial kinetic energy

= 14.09 x 10⁻¹⁹ J (see above )

reduction in kinetic energy  

= 6.64 x 10⁻¹⁹ J ( See above )

Total energy with electron -

= 14.09 x 10⁻¹⁹  - 6.64 x 10⁻¹⁹

= 7. 45 x 10⁻¹⁹ J .

If V be the energy of electrons reaching the negative plate,

1/2 m V² =7. 45 x 10⁻¹⁹

V = 1.28 X 10⁶ ms⁻¹

6 0
4 years ago
Billiard ball A strikes another ball B of the same mass, which is at rest, such that after the impact they move at angles ΘA and
Drupady [299]

Answer:

7.6427m/s

Explanation:

Given:v_a=4.7m/s, \theta_a=33.0\textdegree and \ v_b=4.5m/s

#Applying the conservation of momentum along the x-axis:mv_i=mv_acos\theta_a+mv_bcos\theta_b

#And along y-axis:

0=-sin\theta_a+mv_bsin\theta_b

#Solving  for \theta_b:

sin\rheta_b=\frac{v_a}{v_b}sin\theta_a=4.7/4.5\times sin33.0\textdegree\\=0.5688\\\therefore \theta_b=34.67\textdegree

#By substitution in the x-axis equation:

v_i=4.7cos 33.0\textdegree +4.5cos 34.67\textdegree\\=7.6427m/s

Hence the original speed of the ball before impact is 7.6427m/s

4 0
3 years ago
A charge q produces an electric field of strength 4E at a distance of d away. Determine the electric field strength at a distanc
gizmo_the_mogwai [7]

Answer:

c.) 36E

Explanation:

The magnitude of the electric field is given by the expression

E=k \frac{q}{d^2} (1)

where k is the Coulomb's constant, q is the charge that generates the field, and d is the distance from the charge.

In this problem, we have that the magnitude of the field at a distance d is 4E, so we can rewrite the previous equation as

4E = k\frac{q}{d^2}

Now we want to determine the electric field at a distance of d'=\frac{1}{3}d away. Substituting into (1), we find

E' = k \frac{q}{d'^2}=k \frac{q}{(\frac{1}{3}d)^2}=9 k \frac{q}{d^2} (2)

We also know that

4E = k\frac{q}{d^2} (3)

So combining (2) with (3), we find a relationship between the original field and the new field:

E' = 9 \cdot (4E) = 36E

7 0
3 years ago
An uncharged 30.0-µF capacitor is connected in series with a 25.0-Ω resistor, a DC battery, and an open switch. The battery has
kolezko [41]

Answer:

(a) Maximum current through resistor is 1.43 A

(b) Maximum charge capacitor receives is 1.50\times 10^{-3}\text{ C}.

Explanation:

(a)

In an RC (resistor-capacitor) DC circuit, when charging, the current at any time, <em>t</em>, is given by

I(t) = I_0e^{-t/\tau}

Here, I_0 is the maximum current and <em>τ</em> represents time constant which is given by RC (the product of the resistance and capacitance).

The maximum current is given by

I = \dfrac{V}{R_\text{eff}}

<em>V</em> is the emf of the battery and R_\text{eff} is the effective resistance.

In this question, R_\text{eff} = 10.0 Ω + 25.0 Ω = 35.0 Ω

I = \dfrac{50.0\text{ V}}{35.0\ \Omega} = 1.43\text{ A}

(b) The maximum charge is given

<em>Q</em> = <em>CV</em>

where <em>C</em> is the capacitance of the capacitor

Q = (30.0\times10^{-6}\text{ F})(50.0\text{ V}) = 1.50\times 10^{-3}\text{ C}

3 0
4 years ago
Read 2 more answers
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