AP Physics Rotation Review

What force does not cause any torque?

• Force perpendicular to the fulcrum, and not on the fulcrum
• Force parallel to the fulcrum, and not on the fulcrum
• Force perpendicular to the fulcrum, and slightly off center of the fulcrum
• Forces at a 45 degree angle to the fulcrum, and not on the fulcrum

Does a bridge anchored resting on two pillars have any torque?

• No, it isn't moving
• Yes, but it is at equilibrium
• Yes, but it will soon break because of the torque
• No, Bridges can't have torque

Which of these has the greatest centripetal acceleration?

• Large Velocity, Large Radius
• Small Velocity, Small Radius
• Large Velocity, Small Radius
• Small Velocity, Large Radius

The rotational equivalent to d (distance), v (velocity) and a (acceleration) are?

• m, m/s, m/s²
• θ, ω, α
• x, x/t, alphaα
• μ, Σ, τ

The center of mass is:

• the exact middle
• the heaviest part
• the point at which you can balance with one finger
• the idea that mass is concentrated throughout

How do you get the maximum torque?

• longer lever arm and less force at an acute angle
• shorter lever arm and less force perpendicularly
• shorter lever arm and more force perpendicularly
• longer lever arm and more force perpendicularly

A solid  metal bar is at rest on a horizontal frictionless surface. It is free to rotate about a vertical axis at the left end. The figures show forces of different magnitudes that are exerted on the bar at different locations. In which case does the bar's angular speed about the axis increase at the fastest rate?

• A
• B
• C
• D

Tags

NGSS.HS-PS2-1

In the diagram above, two masses, one with mass m, the other with mass M = 2m are resting on a uniform plank of length L that pivots at its midpoint. If the mass m is at the far end of the plank, how far away from the pivot should the mass M be to balance the plank in a horizontal position shown?

• L/2
• L/3
• L/4
• L/6

Tags

NGSS.HS-PS2-1

Two equal forces do W Joules of work on cylinder (I=¹/₂mr²) and a hoop (I=mr²) of the same radius and same mass.  What is the ratio of the total kinetic energy of the cylinder to the total kinetic energy of the hoop after this work has been done?

• 1:1
• 1:2
• 2:1
• 1:4

Tags

NGSS.HS-PS2-1

NGSS.HS-PS3-1

NGSS.HS-PS3-2

A cylinder (I=¹/₂mr²) and a hoop (I=mr²) of the same radius and same mass are traveling at the same angular velocity (ω).  What is the ratio of the angular momentum of the cylinder to the angular momentum of the hoop?

• 1:1
• 1:2
• 2:1
• 1:4