Rotational Motion Review

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

The figure above shows a uniform meterstick that is set on a fulcrum at its center. A force of magnitude F toward the bottom of the page is exerted on the meterstick at the position shown. At which of the labeled positions must an upward force of magnitude 2F be exerted on the meterstick to keep the meterstick in equilibrium?

• A

• B

• C

• D

Tags

NGSS.HS-PS2-1

What direction is the torque acting with respect to post A?

• clockwise

• Counter clockwise

• Neither Direction

• Depends on the mass of the diver

In order to do a lot of flips an Olympic diver would want:

• high rotational inertia

• low rotational inertia

• low linear acceleration

• low angular velocity

What happens to his rotational inertia when a figure skater brings in his arms?

• Increase his rotational inertia

• Decrease his rotational inertia

• has no affect

Which would have a greater linear velocity?

• Kid near the center of the merry go round

• Kid near the outside of the merry go round

• neither

Tags

NGSS.MS-PS3-1

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

Tags

NGSS.HS-ETS1-3

A long rod is suspended by a frictionless bearing near its top. A lump of clay is projected from the right, collides with the block and sticks to it. Which one of the following statements is correct about the clay and rod system for this collision?

• The mechanical energy, linear momentum and angular momentum remain constant.

• The linear momentum and the angular momentum remain constant but the mechanical energy changes.

• Only the angular momentum remains constant.

• None of the quantities of mechanical energy, linear momentum, or angular momentum remain constant.

Tags

NGSS.HS-PS2-2

An object is spinning. Doubling the mass reduces the ω by half.

• True

• False

You apply force to a wrench to tighten a bolt. The wrench breaks in half. Select the best answer for what happens next. Assume the force applied remains constant.

• The torque is now half of what it was, because torque and distance are inversely proportional

• The torque is now half of what it was, because torque and distance are directly proportional

• The torque is now double of what it was, because torque and distance are inversely proportional

• The torque is now double of what it was, because torque and distance are directly proportional