CH.15

Textbook Questions: 1} If your heart rate is 150 beats per minute during strenuous exercise, what is the time per beat in units of seconds? 2} Find the frequency of a tuning fork that lakes 2.50\"'10'3 s to complete one oscillation. 3} If the spring constant of a simple harmonic oscillator is doubled, by what factor will the mass of the system need to change in order for the frequency of the motion to remain the same? 4} A 0.500-kg mass suspended from a spring oscillates with a period of 1.50 s. How much mass must be added to the object to change the period to 2.00 s? 5] The device pictured to the right entertains babies while keeping them from wandering. The baby bounces in a harness suspended from a door frame by a spring constant. a) [I' the spring stretches 0.250 m while supporting an Ellikg baby. what is its spring constant? b) What is the time for one complete bounce of this baby? c) What is the baby's maximum velocity if the amplitude of her bounce is 0.200 m? G} What is the length of a pendulum that has a period of 0.500 s? 7} a) What is the effect on the period ofa pendttlum ifyou dottble its length? b] What is the effect on the period of a pendulum if you decrease its length by 5.00%? 3} Find the ratio of the newr'old periods of a pendulum if the pendulum were transported from Earth to the Moon, where the acceleration due to gravity is 1.63 mr'sf. 9) Wind gusts create ripples on the ocean that have a wavelength of 5.00 cm and propagate at 2.00 mr's. What is their frequency? 10) Scouts at a camp shake the rope bridge they have just crossed and observe the wave crests to be 3.00 m apart. If they shake it twice per second, what is the propagation speed of the waves? 11] What is the wavelength of the waves you create in a swimming pool if you splash your hand at a rate of 2.00 Hz and the waves propagate at 0.000 mr's? 12) Radio waves transmitted through space at 3.00*l0" mr's by the Voyager spacecraft have a wavelength of 0.120 m. What is their frequency? 1) 0.400 si'beat 2) 400 Hz 3) increase by factor of 2 4) 0.339 kg 5) a] 314 Mm; b) 1.00 s; c) 1.25 refs 6} 6.21 cm '7) a) T increases by a factor of 2: b) new T is 97.5% of original T 8) a) 2.45 9} 40.0 Hz 10) 15.0 rru's 11) 0.400 m 12) 2. 50*10" H