- #1
WinWolfz
I have been assigned the following four questions, and am absolutely lost as to how to solve them. I am NOT looking for someone to solve them for me, however any general hints and tips, as well as pointing at other similar examples or equations would be wonderful! I want to be able to understand these on my own, not just copy someone else's work. Thanks in advance!
1. A baseball player hits a home run that just barely clears the 12-m-high fence in right fi eld—92 m from home plate. If the ball was at a height of 1 m when it was hit, and its initial path after it left the bat was at an angle of 40° above the horizontal, what was the ball's initial speed when it left the bat?
2. While installing an antenna on your roof, you lost your footing and slid off the roof. Fortunately, you placed a safety net whose center is positioned at a horizontal distance of 3.75 m, measured from a point directly below the edge of the roof—and indeed you landed in the center of the net. If the roof slopes downward at a 30° angle below the horizontal, and your speed as you left the roof was 4 m/s, how high was the edge of the roof above the level of the safety net?
3. At the same moment when his teammate punts (kicks) the ball, a football player starts from rest—at a point exactly alongside the kicker—and runs down the level fi eld with constant (non-zero) acceleration,
toward the opponent who is waiting to catch the ball. If the ball leaves the kicker's foot at an angle of 76.0° above the horizontal, what acceleration does the player need in order to arrive and tackle the opponent just as he catches the ball? (Assume the ball is caught at the same height as that from which it was kicked.)
4. A train and a car collided in the night at a rural crossing on level ground. The train track is straight and runs northeast/southwest. At the point of collision (the crossing) the train was traveling northeast at a constant speed of 30 m/s. The road runs east/west, and at the point of collision, the car was traveling east at a constant speed of 20 m/s. What was the speed of impact?
1. A baseball player hits a home run that just barely clears the 12-m-high fence in right fi eld—92 m from home plate. If the ball was at a height of 1 m when it was hit, and its initial path after it left the bat was at an angle of 40° above the horizontal, what was the ball's initial speed when it left the bat?
2. While installing an antenna on your roof, you lost your footing and slid off the roof. Fortunately, you placed a safety net whose center is positioned at a horizontal distance of 3.75 m, measured from a point directly below the edge of the roof—and indeed you landed in the center of the net. If the roof slopes downward at a 30° angle below the horizontal, and your speed as you left the roof was 4 m/s, how high was the edge of the roof above the level of the safety net?
3. At the same moment when his teammate punts (kicks) the ball, a football player starts from rest—at a point exactly alongside the kicker—and runs down the level fi eld with constant (non-zero) acceleration,
toward the opponent who is waiting to catch the ball. If the ball leaves the kicker's foot at an angle of 76.0° above the horizontal, what acceleration does the player need in order to arrive and tackle the opponent just as he catches the ball? (Assume the ball is caught at the same height as that from which it was kicked.)
4. A train and a car collided in the night at a rural crossing on level ground. The train track is straight and runs northeast/southwest. At the point of collision (the crossing) the train was traveling northeast at a constant speed of 30 m/s. The road runs east/west, and at the point of collision, the car was traveling east at a constant speed of 20 m/s. What was the speed of impact?
