- #1
aceXstudent
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I have some questions (or checks) on some problems from a fatty packet our teacher decided to give us for the AP test. If I've already given a possible solution, see if I did it right. Thanks!
Problem 1:
A simple pendulum consists of a mass 1.8kg attached to a string of length 2.3m hanging off a ceiling. A light horizontal string attached to a wall holds the pendulum at an angle of 30* from the vertical.
(a) Draw a free-body diagram.
Tension 1 (T.) - 60* (+y)
Tension 2 (T,) - 0* (+x)
Weight (mg) - 90* (-y)
(b) Calculate the tension in the horizontal string.
Since [T,=T.x], find [T.x] by using trigonometry after finding that [T.y=mg].
(c) The horizontal string is now cut close to the mass, and the pendulum swings. Calculate the speed of the mass at the lowest position.
Here's where I forget what to do. Do I find the period? Then what do I have to do?
Problem 2:
A ball attached to a string of length [L] swings in a horizontal circle with constant speed. The string makes an angle [A] with the vertical, and [T] is the tension. Express your answer with these terms and fundamental constants.
(a) Draw free body diagram.
Tension (T) - A (+y)
Weight (mg) - mg (-y)
(b) Determine the mass of the ball.
Do I use [2(pie)(square root of (l/g))=2(pie)(square root of (m/k))]?
(c) Determine the speed of the ball.
Like the simple pendulum above, I have no idea.
(d) Determine the frequency of the ball.
Since [T=1/f], do I use one of the period equations from part (b)?
This is it (for now). Once again, thanks for your time.
Problem 1:
A simple pendulum consists of a mass 1.8kg attached to a string of length 2.3m hanging off a ceiling. A light horizontal string attached to a wall holds the pendulum at an angle of 30* from the vertical.
(a) Draw a free-body diagram.
Tension 1 (T.) - 60* (+y)
Tension 2 (T,) - 0* (+x)
Weight (mg) - 90* (-y)
(b) Calculate the tension in the horizontal string.
Since [T,=T.x], find [T.x] by using trigonometry after finding that [T.y=mg].
(c) The horizontal string is now cut close to the mass, and the pendulum swings. Calculate the speed of the mass at the lowest position.
Here's where I forget what to do. Do I find the period? Then what do I have to do?
Problem 2:
A ball attached to a string of length [L] swings in a horizontal circle with constant speed. The string makes an angle [A] with the vertical, and [T] is the tension. Express your answer with these terms and fundamental constants.
(a) Draw free body diagram.
Tension (T) - A (+y)
Weight (mg) - mg (-y)
(b) Determine the mass of the ball.
Do I use [2(pie)(square root of (l/g))=2(pie)(square root of (m/k))]?
(c) Determine the speed of the ball.
Like the simple pendulum above, I have no idea.
(d) Determine the frequency of the ball.
Since [T=1/f], do I use one of the period equations from part (b)?
This is it (for now). Once again, thanks for your time.