- #1
Naeem
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Ball in Elevator...
Q.
Ball in Elevator
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A physicist is inside an elevator rising in a skyscraper. She is holding a ball at a height h = 2.1 m above the floor of the elevator.
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a) She let's go of the ball while the elevator is rising at a constant speed of 4.6 m/s. How long does it take the ball to hit the elevator floor?
tto floor = s
2.1/4.6 NO
HELP: The ball and the elevator floor will be at the same height above the ground when the ball hits the floor
I used
x - x0 =v0t + 1/2at^2
Since constant speed acc. is zero.
so,
t = x-xo/vo
2.1 /4.6 which is wrong?
Any one help
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b) Now let's try a somewhat harder variation on this problem. Suppose instead that the elevator is accelerating upward with constant acceleration a = 1.2 m/s2 and that the upward speed of the elevator at the instant the ball is dropped, is 4.6 m/s. Now how long does it take the ball to hit the elevator floor, assuming once again that it is dropped from a height of 2.1 m? Q
No idea here help me, what equations, may be the same one as above, what to plugin, etc.etc.
Q.
Ball in Elevator
--------------------------------------------------------------------------------
A physicist is inside an elevator rising in a skyscraper. She is holding a ball at a height h = 2.1 m above the floor of the elevator.
--------------------------------------------------------------------------------
a) She let's go of the ball while the elevator is rising at a constant speed of 4.6 m/s. How long does it take the ball to hit the elevator floor?
tto floor = s
2.1/4.6 NO
HELP: The ball and the elevator floor will be at the same height above the ground when the ball hits the floor
I used
x - x0 =v0t + 1/2at^2
Since constant speed acc. is zero.
so,
t = x-xo/vo
2.1 /4.6 which is wrong?
Any one help
--------------------------------------------------------------------------------
b) Now let's try a somewhat harder variation on this problem. Suppose instead that the elevator is accelerating upward with constant acceleration a = 1.2 m/s2 and that the upward speed of the elevator at the instant the ball is dropped, is 4.6 m/s. Now how long does it take the ball to hit the elevator floor, assuming once again that it is dropped from a height of 2.1 m? Q
No idea here help me, what equations, may be the same one as above, what to plugin, etc.etc.