Passage II

An object is dropped from a height H above the top of a spring, compressing it. The top of the spring is a distance y below its initial position (see Figure 1) when the spring begins its rebound. At that moment, the object has its maximum upward acceleration, a.

Figure 2 shows, for each of 3 springs—Spring X (the least stiff spring), Spring Y, and Spring Z (the stiffest spring)—a graph of the ratio versus H; g is the acceleration due to gravity.

9. The acceleration due to gravity is approximately 10 . Based on Figure 2, when H equals 8.0 m for Spring Z, what approximately is a ?

Answer and Explanation

Your Answer is

Correct Answer is D

Explanation

Look at figure 2 first, when the abscissa is 8, the ordinate of Spring X is 7;

It is also known that the acceleration of gravity g=10, so a=7×10=70