A low-flving jet aircraft approaches a stationary observer on the ground at a speed of 1000 km/hr on a day when the speed of sound is 345 m/s. (a) If the engine emits a sound of frequency 4000 Hz, what frequency does the stationary observer receive as the plane approaches? (b) As the plane flies away? Si mire barn Circha​

Agroup of students were investigating the force of gravity. they began by dropping a foam ball from a height of 3 meters into a bucket of sand. the ball hit the sand in 0.306 seconds. they dropped additional balls of approximately the same diameter, but of different masses. here is the data they collected. based on this experiment and the collected data, what would their conclusion be?