During a sleet storm, the roadsare covered with frictionless ice. A car of mass
ID: 1724032 • Letter: D
Question
During a sleet storm, the roadsare covered with frictionless ice. A car of mass 1000 kgtraveling
east at a speed of6m/s slams into a stationary truck ofmass 2000 kg. The car and truck do
not stick together after the collision. After the collision,the car is stationary.
1. [5 points] Determine (themagnitude and direction of) the totalmomentum of the
truck plus car systembefore thecollision.
2. [5 points] Determinethe velocity of the center-of-mass(of the truck plus car system)
before the collision.
3. [5 points] Determinethe velocity of the center-of-mass(of the truck plus car system)
after the collision.
4. [5 points] Determinethe velocity of the truck just after the collision.
5. [5 points] Determine the magnitude ofthe impulse onthe truck due to the collision.
Explanation / Answer
Given :. Mass of car (m1) = 1000kg . Initial velocity (u1) = 6 m /s . Mass of truck (m2) = 2000kg . Initial velocity (u2) = 0 . (a) Total momentum before collision : m1 u1 + m2 u2 = (1000 *6 ) + 0 = 6000 kg - m /s . (b) Velocity of center of mass is : m1u1 + m2 u2 / (m1 + m2) = 6000 / 3000 = 2 m /s . (c) Velocity of truck after collision is : . v2 = [ u2 ( m2 - m1 ) + 2 m1 u1 ] / ( m1 + m2 ) . = [ 0 + 2 * 1000*6 ] / (3000) = 12000 /3000 = 4 m /s . Hence velocityofcenter of mass after collision is : . v = ( m1 v1 + m2 v2 ) / ( m1 + m2 ) = (0 + 2000 * 4 ) / 3000 = 2.67 m /s . (d) Velocity of truck after collision is : . v2 = [ u2 ( m2 - m1 ) + 2 m1 u1 ] / ( m1 + m2 ) . = [ 0 + 2 * 1000*6 ] / (3000) = 12000 /3000 = 4 m /s . . v2 = [ u2 ( m2 - m1 ) + 2 m1 u1 ] / ( m1 + m2 ) . = [ 0 + 2 * 1000*6 ] / (3000) = 12000 /3000 = 4 m /s . (e) Impulse : J = m2(v2 - u2 ) = ---------- kg - m/s . Solve it . Hope this helps u!
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.