Inelastic collision: final velocity after collision

In summary: So the answer is -1.84x10^-4. In summary, the change in velocity of the car due to its encounter with the bug is -1.84x10^-4 m/s. The equation used to calculate this was m1v1 + m2v2 = (m1 + m2)v, and the error in the previous attempt was due to not bringing the terms of the difference to a common denominator.
  • #1
emily081715
208
4

Homework Statement


You are driving your 1000-kg car at a velocity of(19 m/s )ι^ when a 9.0-g bug splatters on your windshield. Before the collision, the bug was traveling at a velocity of (-1.5 m/s )ι^.
What is the change in velocity of the car due to its encounter with the bug?

Homework Equations


pi = pf
m1v1 + m2v2 = (m1 + m2)v

The Attempt at a Solution


i attempted to solve for the change in velocity using the equation outlined below and got answer of -3.0x10^-5. i know this answer is inncorrect but i cannot seem to locate my source of error
Δv=(1.9x10^4)+ (-1.35x10^-2) -19 m/s
1000 +0.009
 
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  • #2
emily081715 said:

Homework Statement


You are driving your 1000-kg car at a velocity of(19 m/s )ι^ when a 9.0-g bug splatters on your windshield. Before the collision, the bug was traveling at a velocity of (-1.5 m/s )ι^.
What is the change in velocity of the car due to its encounter with the bug?

Homework Equations


pi = pf
m1v1 + m2v2 = (m1 + m2)v

The Attempt at a Solution


i attempted to solve for the change in velocity using the equation outlined below and got answer of -3.0x10^-5. i know this answer is inncorrect but i cannot seem to locate my source of error
Δv=(1.9x10^4)+ (-1.35x10^-2) -19 m/s
1000 +0.009
Bring the terms of the difference to common denominator, then 1.9x10^4 cancels, and you avoid rounding errors.
 
  • #3
ehild said:
Bring the terms of the difference to common denominator, then 1.9x10^4 cancels, and you avoid rounding errors.
i am unsure what you mean for me to do/ how to do that
 
  • #4
You calculate the difference ##\frac {19\cdot 1000- 1.5\cdot 0.009}{1000+0.009}-19 = \frac{19\cdot 1000- 1.5\cdot 0.009-19(1000+0.009)}{1000+0.009}##
Expand and simplify.
 
  • #5
ehild said:
You calculate the difference ##\frac {19\cdot 1000- 1.5\cdot 0.009}{1000+0.009}-19 = \frac{19\cdot 1000- 1.5\cdot 0.009-19(1000+0.009)}{1000+0.009}##
Expand and simplify.
i got an answer of -1.8449 x10^-4
 
  • #6
emily081715 said:
i got an answer of -1.8449 x10^-4
It looks correct, but do not keep more than 3 significant digits.
 

FAQ: Inelastic collision: final velocity after collision

1. What is an inelastic collision?

An inelastic collision is a type of collision in which some of the kinetic energy of the objects involved is lost during the collision. This results in a decrease in the final velocity of the objects after the collision.

2. How is the final velocity calculated in an inelastic collision?

The final velocity in an inelastic collision is calculated using the equation vf = (m1v1 + m2v2) / (m1 + m2), where vf is the final velocity, m1 and m2 are the masses of the objects, and v1 and v2 are their initial velocities.

3. Can the final velocity be greater than the initial velocity in an inelastic collision?

No, the final velocity in an inelastic collision will always be less than or equal to the initial velocity of the objects involved. This is because some of the kinetic energy is lost during the collision.

4. What factors affect the final velocity in an inelastic collision?

The final velocity in an inelastic collision is affected by the masses and initial velocities of the objects involved. The larger the mass and initial velocity of an object, the greater its final velocity will be.

5. How does an inelastic collision differ from an elastic collision?

An inelastic collision differs from an elastic collision in that in an elastic collision, the objects involved bounce off each other without any loss of kinetic energy. This results in the final velocities being equal to the initial velocities. In an inelastic collision, some of the kinetic energy is lost, resulting in a decrease in the final velocities.

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