1. A heat engine takes in 1000 J of energy at 1000 K and exhausts 615 J at 200 K. What are the actual and maximum theoretical efficiencies of this heat engine?
2. If a mass on a spring takes 14 s to complete five cycles, what is its period?
3. A mass on a spring bobs up and down over a distance of 29 cm from the top to the bottom of its path four times each second. What are its period and amplitude?
4. A girl with a mass of 40 kg is swinging from a rope with a length of 2.8 m. What is the frequency of her swinging?
5. A periodic wave on a string has a wavelength of 24 cm and a frequency of 2.0 Hz. What is the speed of the wave?
6. What is the distance between adjacent crests of ocean waves that have a frequency of 0.18 Hz if the waves have a speed of 2.6 m/s?