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
yKpoI14uk [10]
3 years ago
12

Imagine two billiard balls on a pool table. Ball A has a mass of 7 kilograms and ball B has a mass of 2 kilograms. The initial v

elocity of the ball A is 6 meters per second to the right, and the initial velocity of the ball B is 12 meters per second to the left.
1. When the two balls hit each other, what will happen if it is a perfectly
inelastic collision?

2. Compare the final velocity of the balls.

3. What can you say about the total momentum before and after the collision?
Physics
1 answer:
wlad13 [49]3 years ago
3 0
1) In a perfectly inelastic collision, the two balls stick together after the collision. In this type of collision, the total kinetic energy of the system is not conserved, while the total momentum is conserved.
If we callv_f the final velocity of the two balls that stick together, the conservation of the total momentum before and after the collision can be written as
m_a v_{Ai} + m_b v_{Bi} = (m_A+m_B)v_f (1)
where
m_A=7 kg is the mass of ball A
m_B=2 kg is the mass of ball B
v_{Ai}=6 m/s is the initial velocity of ball A
v_{Bi}=-12 m/s is the initial velocity of ball B (taken with a negative sign, since it goes in the opposite direction of ball A)

If we solve (1) to find v_f, we find that the final velocity of the balls is
v_f= \frac{m_Av_{Ai}+m_Bv_{Bi}}{m_A+m_B}= \frac{(7\cdot 6)+(2 \cdot (- 12))}{7+2}= \frac{18}{9}=2 m/s
and the positive sign means the two balls are going to the right.


2) I assume here we are talking about an elastic collision. In this case, both total momentum and total kinetic energy are conserved:
m_A v_{Ai}+m_B v_{Bi} = m_A v_{fA} + m_B v_{fB}
\frac{1}{2}m_A v_{Ai}^2+ \frac{1}{2}m_B v_{Bi}^2= \frac{1}{2}m_Av_{fA}^2+ \frac{1}{2}m_B v_{fB}^2
where
v_{fA} is the final velocity of ball A
v_{fB} is the final velocity of ball B

If we solve simultaneously the two equations, we find:
v_{fA}= \frac{v_{Ai}(m_A-m_B)+2m_Bv_{Bi}}{m_A+m_B} = \frac{(6)(7-2)+2(2)(-12)}{7+2}=-2 m/s
v_{fB}= \frac{v_{Bi}(m_B-m_A)+2m_Av_{Ai}}{m_A+m_B} = \frac{(-12)(2-7)+2(7)(6)}{7+2}= \frac{144}{9}=16 m/s
So, after the collision, ball A moves to the left with velocity v=-2 m/s and ball B moves to the right with velocity v=16 m/s.

3) The total momentum before and after the collision is conserved.
In fact, the total momentum before the collision is:
p_i = m_A v_{A} + m_B v_{fB} = (7\cdot 6)+(2 \cdot (-12))=42-24=18 m/s
and the total momentum after the collision is:
p_f = m_A v_{A} + m_B v_{fB} = (7\cdot (-2))+(2 \cdot 16)=-14+32=18 m/s

You might be interested in
Which of the following statements describe the transfer of energy?
Lady_Fox [76]

The answer should be A weighlifter lifting 100lb. bell bar from his chest to a certain height.

7 0
3 years ago
How does space promote science education
Fittoniya [83]
<span>NASA and the Mad Science Group of Montreal, Canada, have teamed in an effort to spark the imagination of children, encouraging more youth to pursue careers in science, technology, engineering and math. The two organizations recently signed a Space Act Agreement, officially launching the development of the Academy of Future Space Explorers.</span>
3 0
3 years ago
What is the electric field at the point x=6.5 m? positive e-fields point to the right.?
Mademuasel [1]
6,5   6,4   6,3   6,2   6
if you know,1    
5 0
3 years ago
which of these types of radiation do you suppose we should fear the most if administered internally? •gamma rays •neutrons •alph
4vir4ik [10]
Alpha particles, because they are the heaviest ones (helium nuclei) and will travel around the body.
4 0
3 years ago
A boy flies a kite with the string at a 30 degree angle to the horizontal. The tension in the string is 4.5N .
sp2606 [1]
How much work in J does the string do on the boy if the boy stands still? 

<span>answer: None. The equation for work is W = force x distance. Since the boy isn't moving, the distance is zero. Anything times zero is zero </span>
<span>--------------------------------------... </span>
<span>How much work does the string do on the boy if the boy walks a horizontal distance of 11m away from the kite? </span>

<span>answer: might be a trick question since his direction away from the kite and his velocity weren't noted. Perhaps he just set the string down and walked away 11m from the kite. If he did this, it is the same as the first one...no work was done by the sting on the boy. </span>

<span>If he did walk backwards with no velocity indicated, and held the string and it stayed at 30 deg the answer would be: </span>
<span>4.5N + (boys negative acceleration * mass) = total force1 </span>
<span>work = total force1 x 11 meters </span>
<span>--------------------------------------... </span>

<span>How much work does the string do on the boy if the boy walks a horizontal distance of 11m toward the kite? </span>

<span>answer: same as above only reversed: </span>
<span>4.5N - (boys negative acceleration * mass) = total force2 </span>
<span>work = total force2 x 11 meters</span>
6 0
3 years ago
Other questions:
  • Astronomers have discovered several volcanoes on io, a moon of jupiter. one of them, named loki, ejects lava to a maximum height
    13·1 answer
  • A model rocket is launched straight upward with an initial speed of 57.0 m/s. It accelerates with a constant upward acceleration
    14·1 answer
  • Which of the following is the difference between anecdotal claims and frequency claims?
    7·1 answer
  • Acceleration is the change of
    7·1 answer
  • Is it possible to add three vectors of equal magnitude but a different direction to get a null vector?
    13·1 answer
  • Light reflects off the surface of lake superior. What phase shift does it undergo?
    8·1 answer
  • When the mass of the cylinder increased by a factor of 3, from 1.0 kg to 3.0 kg, what happened to the cylinder’s gravitational p
    12·2 answers
  • The theory that attitudes will be formed and changed according to one’s actual behaviors is the __________ theory. A. learning B
    11·2 answers
  • 2. Which activity requires a scientist to use
    10·2 answers
  • When using higher magnification, you need more light. which parts of the microscope can be adjusted to provide more light, and h
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!