Two stones are launched from the top of a tall building. One stoneis thrown in a
ID: 2169463 • Letter: T
Question
Two stones are launched from the top of a tall building. One stoneis thrown in a direction 30.0^circ above the horizontal with aspeed of 16.0 m {m/s}; the other is thrown in adirection 30.0^circ below the horizontal with thesame speed.Part A
Which stone spends more time in the air?(Neglect air resistance.)
The stone thrown upward
Part B
Which stone lands farther away from the building? (Neglect air resistance.)
They would land in the same spot correct? just at different times...?
Explanation / Answer
If you consider the kinematic eqn for each stone. For the stone thrown 20 deg. above the horizontal: y1 = yo + 10sin20t - 1/2 gt², where y1 is the maximum height of the stone and yo is the height of the building For the stone thrown 20 deg. below the horizontal: y2 = yo - 10sin20t - 1/2 gt², where y2 is the maximum height of the stone. Notice that y1 > y2. Therefore, t in the eqn for y1 will be greater than t in the eqn for y2. So that stone1 will spend more time in the air, since it has more distance to cover before impact