Section 8­1 notes.notebook
December 13, 2011
Torque ­ a quantity that measures the ability of a force to rotate an object around some axis.
Lever Arm ­ the perpendicular distance from the axis of rotation to a line drawn along the direction of the force.
Extended Objects ­ is an object that has a definite, finite size and shape.
Point Mass ­ an object described by its position in space.
d
F
axis of rotation
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Section 8­1 notes.notebook
December 13, 2011
Torque = force x lever arm
τ = Fd(sinθ)
SI Unit of torque is N m Torque is a vector quantity, however for this book it is used only as a scalar quantity. We will assign a sign with the direction positive for counterclockwise and negative for clockwise.
A basketball is being pushed by two players during tip­off. One player exerts a downward force of 11 N at a distance of 7.0 cm from the axis of rotation. The second player applies an upward force of 15 N at a perpendicular distance of 14 cm from the axis of rotation. Find the net torque acting on the ball.
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Section 8­1 notes.notebook
December 13, 2011
Assignment Practice 8A ­ all
Sect 8­1 Rev ­ all
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