A person stands a distance  $\overrightarrow{r}$   from a door’s hinges and pushes with a force  $\overrightarrow{F}$   directed perpendicular to its surface, rotating the door at its hinge with a torque  $\tau$  . What is the applied torque if the person’s position and force change to  $\overrightarrow{2r}$   and  $\overrightarrow{2F}$  , respectively?

•  $\tau$  

•  $2\tau$  

•  $4\tau$  

•  $\frac{\tau}{4}$  

Three forces of equal magnitude are applied to a 3-m by 2-m rectangle as shown. At which labeled point is the net torque the greatest?

• A

• B

• C

• All the same

Signs are suspended from rods of equal length on the side of a building. For each case, the mass of the rod can be ignored. The mass of the sign is given in each figure. Which case has the greatest magnitude of the torque that the sign exerts about the point at which the rod is attached to the side of the building.

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Four forces act on a plywood hexagon as shown in the diagram. The sides of the hexagon each have a length of 1 m. Which force exerts the greatest magnitude of torque applied about the center of the hexagon?

• A

• B

• C

• D

Each of the ten point masses in each case is identical. The rods connecting the masses are very light. The solid line in each figure represents an axis about which the masses are going to be rotated. The point masses are fixed together so that they all maintain the arrangements shown while being rotated. Which arrangement has the greatest moment of inertia at its axis?

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A 2-m long massless rod supports a 12-Newton weight. The left end of each rod is held in place by a frictionless pin. In each case, a vertical force F is holding the rods and the weights at rest. The rods are marked at half-meter

intervals. Which case has a force F with the greatest magnitude?

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Tags

NGSS.HS-PS2-1

A rod is made of three segments of equal length with different masses. The total mass of the rod is 6m. At which axis on the rod will it be most difficult to rotate the rod?

• left end

• right end

• between m and 2m

• between 2m and 3m

In each of the given figures, the diameters of the disks  $D$  , the masses of the disks  $m$  , and the masses of the hanging masses are given. The disks are fixed and are free to rotate at their centers. Which disk has the greatest angular acceleration?

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Tags

NGSS.HS-PS2-1

A solid sphere rolls without slipping along a track shaped as shown. It starts from rest at point A and is moving vertically when it leaves the track at point B. At what vertical height will the sphere reach as it flies off from point B?

• above A

• below A

• equal to A

• cannot tell from what are given

Tags

NGSS.HS-PS2-1

NGSS.HS-PS3-1

In each case, a 1-kg object is released from rest on a ramp at a height of 2 m from the bottom. All of the spheres roll

without slipping, and the block slides without friction. Which object will reach the greatest height on the other side of the ramp?

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• All objects will reach the same height.

Tags

NGSS.HS-PS3-1