rotation and torque

A state of equilibrium is also seen below. Each of the cars weighs the same  9800 N. Despite the fact that there is only one car on the left-hand side that is 9 m from the fulcrum, the torques balance because, the car on the left-hand side, is ____meters from the fulcrum, compared to the cars on the right-hand side.

• 4.5 m
• 3 m
• 1 m
• 2 m

A seesaw is unbalanced with two people of different masses sitting equal distances from the center. Which of the following will result in equilibrium?

• The larger person moving further away from the center.
• Moving the smaller person closer to the center.
• Moving the smaller person further from the center.
• Making the larger person do nothing.

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

A wrench is used to tighten a nut. A 15N perpendicular force is applied 50cm away from the axis of rotation, and moves a distance of 10 cm as it turns. What is the torque applied to the wrench?

• 7.5 Nm
• 1.5 Nm
• 750 Nm
• 150 Nm

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.MS-PS2-4

When an object is experiencing a net torque

• it is in dynamic equilibrium.
• it is in static equilibrium.
• it is rotating.
• it is translating.

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 is the distance the masses on the right of the fulcrum need to be to balance with the two masses on the left?

• .65 m
• .56 m
• .79 m
• .39 m

Tags

NGSS.MS-PS2-4

A uniform rod weighs 40 N and is 1.0 m long. It is hinged to a wall at the left end, and held in a horizontal position at the right end by a vertical string of negligible weight, as shown in the figure. What is the magnitude of the torque due to the string about a horizontal axis that passes through the hinge and is perpendicular to the rod? The hinge is very small with negligible friction.

• 5.0 N ∙ m
• 20 N ∙ m
• 10 N ∙ m
• 40 N ∙ m

A 15-kg child is sitting on a playground teeter-totter, 1.5 m from the pivot. What is the magnitude of the minimum force, applied 0.30 m on the other side of the pivot, that is needed to make the child lift off the ground?

• 66 N
• 740 N
• 23 N
• 44 N

Tags

NGSS.MS-PS2-2

A woman sits on a spinning piano stool with her arms folded. When she extends her arms, which of the following occurs?

• She increases her moment of inertia, thereby increasing her angular speed.

• She increases her moment of inertia, thereby decreasing her angular speed.

• She decreases her moment of inertia, thereby increasing her angular speed.

• She decreases her moment of inertia, thereby decreasing her angular speed.