A soccer player kicks a rock horizontally off a 31.5 m high cliff into a pool of water. If the player hears the sound of the splash 3.6 s later, what was the initial speed given to the rock? Assume the speed of sound in air to be 343 m/s.
I don't get how to use the speed of sound...
The force exerted by the wind on the sails of a sailboat is 360 N north. The water exerts a force of 250 N east. If the boat (including its crew) has a mass of 270 kg, what are the magnitude and direction of its acceleration?
2007-09-19 17:14:19 · 1 answers · asked by christian8807 3 in Science & Mathematics ➔ Physics
1.
Use the speed of sound to find the distance between the player and the place where the rock hit the water. Next find the horizontal distance between the cliff and the place where the rock hit the water (Pythagoras). Next find the time of the flight of the rock (free fall). Next find the initial speed of the rock.
2.
Add both forces as vectors. Find acceleration from 2nd Newton law. (Direction of the acceleration is the same as direction of the force.)
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2007-09-19 18:36:06 · answer #1 · answered by oregfiu 7 · 0⤊ 0⤋