A ball is thrown straight up from the edge of
the roof of a building. A second ball is dropped
from the roof 1.00 s later. You may ignore air
resistance.
(a) If the height of the building is 20.0 m, what
must the initial speed of the first ball be if
both are to hit the ground at the same time?
On the same graph, sketch the position of
each ball as a function of time, measured
from when the first ball is thrown. Consider
the same situation, but now let the initial
speed v0 of the first ball be given and treat
the height ℎ of the building as an unknown.
(b) What must the height of the building be for
both balls to reach the ground at the same
time (i) if v0 is 6.0 m/s and (ii) if v0 is 9.5
m/s?
(c) If v0 is greater than some value vmax, a value
of ℎ does not exist that allows both balls to
hit the ground at the same time. Solve for vmax. The value vmax has a simple physical
interpretation. What is it?
(d) If v0 is less than some value vmin, a value of
ℎ does not exist that allows both balls to hit
the ground at the same time. Solve for vmin.
The value vmin also has a simple physical
interpretation. What is it?
여기서 vmax 랑 vmin이 뭘 말하는지 모르겠어요
미니멈 벨로시티 맥시멈 벨로시티겄지
수직으로 위로 던지는 공 a와 a 1초 뒤에 던지는 공 b 가 있고 a 의 v0가 미니멈 벨로시티보다 작은 경우 a,b 같이 떨어지는 경우가 없다는데 여기서 미니멈 벨로시티가 뭘 말하는지 모르겠어요. 저는 벨로시티라 방향성이 있으니까 아래로 떨어지는게 +라면 v0가 미니멈 벨로시티라고 생각이 되서 너무 헷갈리네요
그냥 윗방향으로 던질때의 속력만 봐라 지금 문제에서 h로 주어졌기때문에 1m위에서던지던 0.5m 위에서 던지던 동시에떨어지는게 불가능한 높이를 찾아서 속도를 구해야한다 - dc App
미니멈이면 높이가 아주높을거고 맥시멈이면 높이가 아주낮겠지 - dc App