1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Semenov [28]
3 years ago
5

A railroad car of mass 2.50 3 104 kg is moving with a speed of 4.00 m/s. It collides and couples with three other coupled railro

ad cars, each of the same mass as the single car and moving in the same direction with an initial speed of 2.00 m/s. (a) What is the speed of the four cars after the collision? (b) How much mechanical energy is lost in the collision?
Physics
1 answer:
ipn [44]3 years ago
4 0

Answer:2.5 m/s

37.5KJ

Explanation:

Let u_1, u_2 , v_f be the initial velocity of rail road car ,coupled cars & Final velocity of system respectively.

m=2.50\times 10^{4}

Conserving momentum

mu_1+3mu_2=4mv_f

4m+6m=4mv_f

v_f=2.5 m/s

Therefore Final velocity of system is 2.5m/s

(b)Mechanical Energy lost =Initial Kinetic Energy -Final Kinetic Energy

Initial Kinetic Energy=\frac{1}{2}m\left ( 4^2\right )+\frac{1}{2}m\left ( 2^2\right )=14m J

Final Kinetic Energy=\frac{1}{2}4m\left ( 2.5^2\right )=12.5m J

Mechanical Energy lost=14m-12.5m=3.75\times 10^4=37.5 KJ

You might be interested in
Answer the attached question.<br>No Spam!<br>⚔️⚔️⚔️​
RoseWind [281]
<h3>Question:5</h3>

The given data can be written in following way in coordinates axes.

(0,0), (2,2), (4,4), (6,4), (8,4), (10,6),(12,4), (14, 2).

a) Average velocity for first 4 seconds

Average velocity = Total Displacement/ Time taken

= (4-0)/(4 - 0)

=4/4

= 1/1

<h3> =1 m/s</h3>

b) Average velocity for 4 to 8 seconds

Average velocity = Total Displacement/ Time taken

= (4 - 4)/(8-4)

= 0/4

<h3> = 0</h3>

c) Average velocity for last 6 seconds

Last 6 seconds = from 8 to 14 seconds

Average velocity = Total Displacement/Time taken

= (2 - 4)/(14 - 8)

= -2/6

<h3> = -1/3 m/s</h3>

<h3>Question 6:</h3>

The given data can be written in following way in coordinates axes.

(0,0), (10,20), (20,20), (30,20), (40,0)

a) State the kind of motion from Os to 10s and from 30s to 40s

It is obvious from the graph that the velocity between Os to 10s has been increased from 0 m/s to 20m/s. Hence there is a uniform Acceleration in the body.

b) What is the velocity of the body after 10s and 40s ?

It is clear from the graph and table as well that,

<h3>Velocity after 10s is 20m/s</h3>

and

<h3>Velocity after 40s is 0 m/s</h3>

c) Calculate the distance covered by the body between 10s to 30s.

Distance covered by the body between 10s to 30s will be given by area of rectangle ABCD

Area of rectangle ABCD= (30 - 10) × (20 - O)

=20×20

<h3> = 400 m</h3>

6 0
2 years ago
using mass and distance, identify and compare the sun's and moon's contribution to the formation of tides on earth
vekshin1

Answer:

Based on its mass, the sun's gravitational attraction to the Earth is more than 177 times greater than that of the moon to the Earth.

7 0
3 years ago
John recently suffered a blow to his head. Since then, he finds it difficult to comprehend what others say to him. He also finds
katovenus [111]

Answer: ​Wernicke's aphasia

Explanation:

John recently suffered a blow to his head. Since then, he finds it difficult to comprehend what others say to him. He also finds it difficult to express his thoughts and cannot seem to find the right words to say while speaking. However, he can speak freely with proper syntax. In this scenario, John is most likely suffering from Wernicke's aphasia.

Wernicke's aphasia occurs when the leftward side of the middle of the brain is damaged or has been altered. An individual who suffers from Wernicke's aphasia will have difficulty in speaking in meaningful and coherent sentences or may have difficulty in understanding the speech of others.

6 0
3 years ago
Which of the following is not a means to accelerating?
GenaCL600 [577]
The answer is B. Remain still.
8 0
2 years ago
A constant torque of 3 Nm is applied to an unloaded motor at rest at time t = 0. The motor reaches a speed of 1,393 rpm in 4 s.
irakobra [83]

Answer:

The moment of inertia of the motor is 0.0823 Newton-meter-square seconds.

Explanation:

From Newton's Laws of Motion and Principle of Motion of D'Alembert, the net torque of a system (\tau), measured in Newton-meters, is:

\tau = I\cdot \alpha (1)

Where:

I - Moment of inertia, measured in Newton-meter-square seconds.

\alpha - Angular acceleration, measured in radians per square second.

If motor have an uniform acceleration, then we can calculate acceleration by this formula:

\alpha = \frac{\omega - \omega_{o}}{t} (2)

Where:

\omega_{o} - Initial angular speed, measured in radians per second.

\omega - Final angular speed, measured in radians per second.

t - Time, measured in seconds.

If we know that \tau = 3\,N\cdot m, \omega_{o} = 0\,\frac{rad}{s }, \omega = 145.875\,\frac{rad}{s} and t = 4\,s, then the moment of inertia of the motor is:

\alpha = \frac{145.875\,\frac{rad}{s}-0\,\frac{rad}{s}}{4\,s}

\alpha = 36.469\,\frac{rad}{s^{2}}

I = \frac{\tau}{\alpha}

I = \frac{3\,N\cdot m}{36.469\,\frac{rad}{s^{2}} }

I = 0.0823\,N\cdot m\cdot s^{2}

The moment of inertia of the motor is 0.0823 Newton-meter-square seconds.

5 0
2 years ago
Other questions:
  • Donna stretched a spring to increase its length. Nearby in an electrical device, a positive charge attracted a negative charge.
    14·1 answer
  • True or False: If a point charge has electric field lines that point into it, the charge must be positive.
    5·1 answer
  • How many microliters are in one liter
    11·2 answers
  • Find the magnitude of vector A = i - 2j + 3k O V14 10 O4
    15·1 answer
  • A rocket moves through outer space at 11,000 m/s. At this rate, how much time would be required to travel the distance from Eart
    10·1 answer
  • Two ice skaters are at rest, Abby
    5·2 answers
  • What does it ​mean​ to go 20 m/s?
    9·1 answer
  • An electric lamp consumes 60W at 220 volts. How many dry cells of 1.5 V and internal resistance 1 Ohm are required to glow the l
    8·1 answer
  • How high should a box of mass 20kg is lifted to store energy of 10,000 J? (g=10m/s)​
    11·1 answer
  • I have no idea so i'm screwed please help me
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!