An object undergoes simple harmonic motion along the x-axis shown above, where x = 0 is the object's equilibrium position. Which of the following graphs best shows the relationship between the object's acceleration a and its displacement x from equilibrium? (Assume positive acceleration to be directed to the right.)

Ajet plane has a sound level of 120 db at a distance of 60 m. what is the q23. sound level at a distance of 6.0 km? (60)2 (6000)? om solution 80db db, hint: 16x assume ultrasound waves travel through the body of an animal at 1540 q24. m/s. if a 30,000 hz signal were reflected off a portion of a heart which was moving toward the source at 3 m/s, what frequency signal would return to the stationary source? solution 30.117hz

This is for my 8th grade science class, i really don’t understand. can someone me? , lol.

Coal contains energy. a. light b. kinetic c. chemical d. mechanical