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A month ago
A 19.5 kg object moving in the +x direction at 5.5 m/s collides head-on with a 15.0 kg object moving in the −x direction at 4.5 m/s
A)Find the final velocity of each mass if the objects stick together.
Express your answers using two significant figures. Enter your answers numerically separated by a comma.
B)Find the final velocity of each mass if the collision is elastic.
Express your answers using two significant figures. Enter your answers numerically separated by a comma.
C) Find the final velocity of each mass if the 19.5 kg object is at rest after the collision.
Express your answers using two significant figures. Enter your answers numerically separated by a comma.
D)Is the result in part C "reasonable"? Explain.
E)Find the final velocity of each mass if the 15.0 kg object is at rest after the collision.
Express your answers using two significant figures. Enter your answers numerically separated by a comma.
F)Is the result in part E "reasonable"? Explain.
G)Find the final velocity of each mass if the 19.5 kg object has a velocity of 4.5 m/s in the −x direction after the collision.
Express your answers using two significant figures. Enter your answers numerically separated by a comma.
H)Is the result in part G "reasonable"? Explain.
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Answer rejected by topic starter
wrote...
Donated
Trusted Member
A month ago
Found online, like before diff numbers but same question Smiling Face with Horns

Quote
A 18.0 kg object moving in the +x direction at 6.0 m/s collides head-on with a 14.0 kg object moving in the -x direction at 3.5

A) Find the final velocity of each mass if the objects stick together.
B) Find the final velocity of each mass if the collision is elastic.
C) Find the final velocity of each mass if the 18.0 object is at rest after the collision.
D) Is the result in part C "reasonable"? Explain.
E) Find the final velocity of each mass if the 14.0 object is at rest after the collision.
F) Is the result in part E "reasonable"? Explain.
G) Find the final velocity of each mass if the 18.0 object has a velocity of 3.5 in the -x direction after the collision.
H) Is the result in part G "reasonable"? Explain.

Answers

A) use
M1V1 + M2V2 = V3(M1+M2)
M1 = 18.0 kg, V1 = +6.0 m/s
M2 = 14.0 kg, V2 = -3.5 m/s
solve for V3

B) this is elastic so both momentum and mechanical energy are conserved
use
M1V1 + M2V2 = M1V3 + M2V4
solve for V3 in terms of V4
then
substitute for V3 in
M1V1 + M2V2 = M1V3 + M2V4
the only variable will be V4
solve for V4
then go back to momentum equation to get V3

C) the 'reasonable' check would be to see if energy is conserved
run the momentum equation to find the missing V
M1V1 + M2V2 = M1V3 + M2V4
then run it through the energy equation
M1V1 + M2V2 = M1V3 + M2V4
I'll bet that the energy equation fails
so
the result of the momentum equation is 'not reasonable'
wrote...
Staff Member
A month ago
Missing d) though h)
- Master of Science in Biology
- Bachelor of Science (Biology)
- Bachelor of Education
wrote...
3 weeks ago
I do appreciate the help guys.
wrote...
Educator
3 weeks ago
I do appreciate the help guys.

@Biala, if you get a chance, please upload the answers you put for reference sake. Would like to see how this one's done
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