Question

Two blocks on a frictionless horizontal surface are on a collision course.One block with mass 0.25 kg moves at 1 m/s to the right collides with a 0.5 kg mass at rest and the two masses stick together. What is the final speed of the blocks after the collision?

          a) -0.33 m/s

          b) +0.33 m/s

          c) 3.27 m/s

          d) 0.67 m/s

          e) 0.25 m/s

Answer 1

To relsove this problem we have should know over Momentum

Step 1.

Definition:

Momentum: In an inelastic collision, some of the kinetic energy of the colliding bodies is converted into other forms of energy such as heat or sound. Examples include traffic collisions, in which the effect of lost kinetic energy can be seen in the damage to the vehicles; electrons losing some of their energy to atoms (as in the Franck Hertz experiment); and particle accelerators in which the kinetic energy is converted into mass in the form of new particles.

In a perfectly inelastic collision (such as a bug hitting a windshield), both bodies have the same motion afterwards. If one body is motionless to begin with, the equation for conservation of momentum is

  

Step 2.

ANSWERS.

   How the block B is at rest the velocity is zero

   the correct answers is the option B

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