4. A wrecking ball is hanging at the end of a long cable on a crane. A student builds a small model of the wrecking ball. The model has a length of 0.500m. The student observes that in swinging back and forth over a small amplitude, the real wrecking ball makes one complete oscillation in the time it takes his model to complete five oscillations. What is the length of the real cable? (12.5m)