[poll id=”35″]
ANSWER: A. 10 seconds
Visualize the problem as a vector, and find the y component of it: (100m/s)(sin30)=50m/s
This means the cannon traveled 50 meters up, and 50 meters down in the y direction. Gravity is 10m/s^2, thus it took 5 seconds to go up, and another 5 seconds to go down, totaling an air time of 10 seconds.