Passage V

Two studies of 6 trials each were performed with sev­eral projectiles, blocks, and springs.

In each trial, the following occurred: First, a spring having a spring constant of k (a measure of the spring's stiffness) was attached to a block of mass M_b. Next, the block was placed on a frictionless horizontal surface such that the spring was neither stretched nor compressed. Then, a projectile of mass m_p was launched toward the block with a velocity v. Upon impact, the projectile became stuck in the block. The force of the impact compressed the spring by a maximum distance x. Figure 1 illustrates the sequence of events beginning with the launch.

The values of m_p and v were used to calculate KE, the projectile's kinetic energy prior to impact. The values of kand x were used to calculate PE, the elastic potential energy that was stored in the spring when it was at maximum compression.

Study 1

In Trials 1-6, various combinations of m_p and v were tested while M_b equaled 2.0 kg and k equaled 3.0 newtons per meter (N/m). Table 1 shows the value of x, and the values of KE and PE (in millijoules, mJ), for each trial.

Study 2

In Trials 7-12, various combinations of M_b and k were tested while m_p equaled 0.010 kg and v equaled 15 m/sec. See Table 2.