Acolumn of soldiers, marching at 121 steps per minute, keep in step with the beat of a drummer at the head of the column. it is observed that the soldiers in the rear end of the column are striding forward with the left foot when the drummer is advancing with the right. what is the approximate length of the column? (take the speed of sound to be 343 m/s.)

Aknife blade is a(n) a. lever b. screw c. wedge d. inclined plane

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?

James joule carefully measured the difference in temperature of the water at the top and bottom of a waterfall. why did he expect a difference