1. You want to determine the period of motion T of a block of unknown mass hung on a spring of unknown spring constant. You hung the mass on the spring and notice that the spring stretches by 14cm as it is holds the block motionlessly. Then, you give the block a slight nudge upwards and you notice that it starts oscillating. Can you determine the period of oscillation? 2. The equation of motion of mass attached to a spring is = 2.95 cos 3.5 , where is in units of meters and in seconds. The mass is 0.48 kg. Find the (a) amplitude, (b) frequency, (c) total energy, (d) potential energy and kinetic energy when = 1.57 .

4. A pendulum has a period of 0.97 s. (a) What is its length? (b) What is the pendulum's period on the Moon where = 1.622 /!? (c) What should be the length of the pendulum on the Moon if its period is 1.0 sec? 5. You want to tune a grandfather clock by adjusting its length. (You do this by tweaking the position of the pendulum bob.) The clock runs five minutes late every 24 hours. If the pendulum's length is , what should be its new length (e.g., what fraction of ) such that the clock is on time? The speed of electromagnetic waves is 3.0 10" /. Find the wavelengths of (a) Bluetooth signal at 2.4 GHz, (b) cell phone signal at 900 MHz, and (c) AM radio signal at

1 MHz. Radio waves are much longer in wavelength compared to cell phone or Bluetooth signal! 7. An earthquake happens in the middle of the ocean. The compressional waves (P waves) travel through the ocean bottom at 5.3 mi/sec, while the tsunami travels at 600 mi/hr. (a) If a coastal area is 1500 miles from the earthquake's epicenter, how much later does the tsunami arrive after the earthquake waves are felt? (b) If the time delay between the earthquake and tsunami arrivals are exactly 3.0 hr, how far away is the epicenter of the earthquake?