Q. A 86 arrow is fired from a bow whose string exerts an average force of 130 on the arrow over a distance of 79 .What is the speed of the arrow as it leaves the bow?
Q. At a height of 5 meters above the surface of a lake, a sound pulse is generated. The echo from the bottom of the lake returns to the point of origin 0.130 s later. The air and water temperatures are 20°C. How deep is the lake?