Question

A student runs an experiment in which a block of known mass is moving across a horizontal table in an xy-coordinate plane. As the block reaches the origin of the coordinate system, the block explodes into two pieces of masses m1 and m2. During the experiment, the velocity of the block 1.0 second before the explosion and the velocity of the two pieces 1.0 second after the explosion are measured using a motion sensor. Conservation of momentum is applied using the masses of the two pieces. However, when the velocity of the piece of mass m2 is calculated, the measured value is 10% less than the calculated value. Which of the following statements best explains the difference in the calculated and measured velocity?

Answer 1

Answer:

Explanation:

The options are:

a) As the block is moving across the table, friction will affect the block’s motion and thus could account for the difference.

b) It is possible that a small amount of the original block was lost during the explosion.

c) When the student did the calculation, the student assumed that the explosion occurred just as the block reached the origin.

d) The difference in velocity could be due to the explosion occurring either just before or just after the origin.

e) The explosion created a force that affected the experiment. Conservation of momentum is not the correct equation to apply to the explosion, since the two pieces apply forces to each other.

The option b) is not possible due to conservation of mass. Explosion time and location in option c) and d) do not affect the calculation. Option e) is not right as internal forces do not affect conservation of momentum.

The correct answer is a) As the block is moving across the table, friction will affect the block’s motion and thus could account for the difference.