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
Natali [406]
1 year ago
10

A 500 kg sack of coal falls vertically onto a 2000 kg railroad flatcar which was initially moving horizontally at 3 m/s. no exte

rnal forces, including friction, act on the flatcar. after the sack rests on the flatcar, the speed of the flatcar is:
Physics
1 answer:
Zinaida [17]1 year ago
6 0

Since there are no external forces, including friction, act on the flatcar. after the sack rests on the flatcar, we would assume that momentum is conserved. This means that

total momentum of car before collision = total momentum of car after collision.

Recall,

momentum = mass x velocity

From the information given,

mass of car before collision = 2000

velocity of car before collision = 3

Thus,

total momentum of car before collision = 2000 x 3 = 6000

Also,

mass of sack = 500

mass of car and sack after collision = 500 + 2000 = 2500

velocity after collision = v

momentum after collision = 2500 x v = 2500v

Since momentum is conserved, then

6000 = 2500v

v = 6000/2500

v = 2.4

the speed of the flatcar is 2.4 m/s

You might be interested in
When a bow is stretched back and an arrow is shot, what type of energy conversion has occurred?
Lelechka [254]
D. mechanical to elastic
6 0
3 years ago
Over millions of years weathered rock soil dead plant and animal remains are pressed and cemented together under the ground form
Eduardwww [97]

Answer:

true

Explanation:

The statement being made is completely true. This layer of rock is called a Sedimentary Rock level and is slowly formed over millions of years with minerals and organic remains from the bottom of the Oceans that may no longer be covered in water anymore. Since it is made up of all these minerals and remains, it is studied widely by Geologists and Archeologists to better understand the Earth's past.

5 0
3 years ago
Which of the following is a chemical equation that accurately represents what happens when a sulfur and oxygen are produced from
Ksenya-84 [330]
It's c................
5 0
3 years ago
vA 61.2-kg circus performer is fired from a cannon that is elevated at an angle of 57.8 ° above the horizontal. The cannon uses
dsp73

Answer:

The effective spring constant of the firing mechanism is 1808N/m.

Explanation:

First, we can use kinematics to obtain the initial velocity of the performer. Since we know the angle at which he was launched, the horizontal distance and the time in which it's traveled, we can calculate the speed by:

v_0_x=\frac{x}{t}\\ \\v_0\cos\theta=\frac{x}{t}\\\\v_0=\frac{x}{t\cos\theta}

(This is correct because the horizontal motion has acceleration zero). Then:

v_0=\frac{20.8m}{(2.60s)\cos57.8\°}\\\\v_0=15.0m/s

Now, we can use energy to obtain the spring constant of the firing mechanism. By the conservation of mechanical energy, considering the instant in which the elastic band is at its maximum stretch as t=0, and the instant in which the performer flies free of the bands as final time, we have:

E_0=E_f\\\\U_e=K\\\\\frac{1}{2}kx^2=\frac{1}{2}mv^2\\\\\implies k=\frac{mv^2}{x^2}

Then, plugging in the given values, we obtain:

k=\frac{(61.2kg)(15.0m/s)^2}{(2.76m)^2}\\\\k=1808N/m

Finally, the effective spring constant of the firing mechanism is 1808N/m.

3 0
3 years ago
How much energy (in kilojoules) is required to convert 200 mL of diethyl ether at its boiling point from liquid to vapor if its
LiRa [457]

Answer:

55.96kJ

Explanation:

Energy = mass of diethyl ether × enthalpy of vaporization of diethyl ether

Volume (v) = 200mL, density (d) = 0.7138g/mL

Mass = d × v = 0.7138 × 200 = 142.76g

Enthalpy of vaporization of diethyl ether = 29kJ/mol

MW of diethyl ether (C2H5)2O = 74g/mol

Enthalpy in kJ/g = 29kJ/mol ÷ 74g/mol = 0.392kJ/g

Energy = 142.76g × 0.392kJ/g = 55.96kJ

4 0
3 years ago
Other questions:
  • Ana poured equal amounts of water into four bowls. Then she put the bowls in the sun for different amounts of time. She recorded
    7·2 answers
  • SomeOne please help me will give BRAILIEST!!!!!!!!
    5·2 answers
  • Two things you can do to increase the acceleration of an object
    13·1 answer
  • The structure of which substances tends to exhibit the greatest hardness?
    14·1 answer
  • You are a support technician working in a data closet in a remote office. You suspect that a connectivity problem is related to
    15·1 answer
  • A falling back in mid air has what
    14·1 answer
  • The process by which people walk
    12·2 answers
  • speed is the ratio of the distance an object moves to a. the direction the object moves. b. the amount of time needed to travel
    10·2 answers
  • What factor from the choices below determines whether
    15·1 answer
  • In this diagram, heat energy is being added over time. The vertical axis shows an increase in temperature, and the horizontal ax
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!