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An automobile of mass 2000 kg is driven into a brick wall in a safety test. The bumper behaves like a Hooke’s-law spring. It has an effective spring constant of 4 × 106 N/m, and is observed to compress a distance of 1.39 cm as the car is brought to rest. What was the initial speed of the automobile? Answer in units of m/s.

User Shurrok
by
8.3k points

1 Answer

4 votes

Answer:0.621 m/s

Step-by-step explanation:

Given

mass of automobile
m=2000 kg

Effective spring constant
k=4* 10^6 N/m

compression in spring
x=1.39 cm

Conserving Energy i.e. Kinetic energy of automobile=Elastic potential Energy of spring


(mv^2)/(2)=(kx^2)/(2)


(2000\cdot v^2)/(2)=(4* 10^6* (1.39* 10^(-2))^2)/(2)


v^2=(4* 1.39^2* 10^2)/(2000)


v=0.621 m/s

User Karthy Sbk
by
8.8k points
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