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Please help me! In a collision, Kara Less who was traveling at 11 m/s while texting in her 1300 kg car, is struck by another vehicle and finds herself and her phone suddenly moving 2.5 m/s in the opposite direction. What impulse does she experience? SHOW WORK

Answer Choices

A. -12,000
B. -14,000
C. -16,000
D. -18,000

Respuesta :

Answer:

D. -18,000

Explanation:

Let's define impulse :

  • Impulse is defined as the product of Force ( N ) applied on the body and the time of impact ( s ) or
  • The change in momentum

hence in this question ,

kara is initially moving with the :

  • velocity [tex]v_{i}[/tex] = 11 [tex]ms^{-1}[/tex]
  • finally moving with velocity [tex]v_{f}[/tex] = -2.5 [tex]ms^{-1}[/tex]    (minus as she moves in the opposite direction )

therefore the initial momentum [tex]p_{i}[/tex] = [tex]m*v_{i}  = 1300*11 = 14300 kgms^{-1}[/tex]

and the final momentum [tex]p_{f}[/tex] = [tex]m*v_{f} = 1300*-2.5= 3250 kgms^{-1}[/tex]

thus the change in momentum : [tex]p_{f}[/tex] - [tex]p_{i}[/tex]

= -3250-14300 = -17550 [tex]kgms^{-1}[/tex] ≅ -18000[tex]kgms^{-1}[/tex]

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