AP Physics unit 8

There are only two forces exerted on the simple meter stick shown in the figure (imagine it is floating in space, for example). The stick is otherwise free to move. The forces are exerted at theta is equal to 30 degrees measured from the meter stick. When measured with respect to an axis through the center of the meter stick, the net torque resulting from the forces exerted on the meter stick is _______. 12.5 N*m 25.0 N*m 43.3 N*m 6.25 N*m 21.7 N*m

12.5 N*m

There are only two forces exerted on the 1-meter long stick shown in the figure (imagine it is floating in space, for example). The stick is not uniform, with its center of mass 70 cm from the left end of the stick, as indicated by point A in the figure. When measured with respect to an axis through the center of mass (point A), the magnitude of the net torque resulting from the forces exerted on the stick is _______. 38 N*m 11.4 N*m 0 N*m 26.6 N*m 15.2 N*m

15.2 N*m

What does the scale read? 500 N 1000 N 2000 N 4000 N

2000 N

There are only two forces exerted on the 1-meter long stick shown in the figure (imagine it is floating in space, for example). The stick is not uniform, with its center of mass 70 cm from the left end of the stick, as indicated by point A in the figure. The net force exerted on the meter stick is _______. 17 N 0 N 38 N 76 N

76 N

There are only two forces exerted on the simple meter stick shown in the figure (imagine it is floating in space, for example). The stick is otherwise free to move. The net force exerted on the meter stick is _______. 0 N 17 N 76 N 38 N

76 N

Hooke's law describes the force of Gravity. A spring. Collisions. Tension. None of the above

A spring.

What kind of stress is being applied to the cylinder in the figure? Shear Volume Tensile Compressive

Compressive

An object will be stable if Its center of gravity is below its highest point. Its center of gravity lies over its base of support. Its center of gravity lies outside its base of support. The height of its center of gravity is less than 1/2 its total height.

Its center of gravity lies over its base of support.

If you are performing the weightlifting exercise known as the strict curl, the tension in your biceps tendon is Larger than the weight you are lifting. Equal to the weight you are lifting. Smaller than the weight you are lifting.

Larger than the weight you are lifting.

An old-fashioned tire swing exerts a force on the branch and a torque about the point where the branch meets the trunk. If you hang the swing closer to the trunk, this will ____ the force and ____ the torque. Increase, increase Not change, increase Not change, not change Not change, decrease Decrease, not change Decrease, decrease

Not change, decrease

What are the appropriate units for stress? Pa/m N*m N N/m Pa

Pa

A person with mass M stands on a ladder of mass m that leans against a frictionless vertical wall and makes an angle of 53° measured from the horizontal. The ladder does not slip on the horizontal surface due to a static frictional force between the ladder and the ground. Some of the forces exerted on the ladder can produce torques on the ladder. Using the contact point between the ladder and the ground as a reference, which force(s) exerted on the ladder produce clockwise torques? The force of the wall on the ladder The force of the wall on the ladder and the static frictional force between the ladder and the ground The weight of the ladder and the weight of the person The weight of the ladder, the weight of the person, and the static frictional force between the ladder and the ground The weight of the ladder, the weight of the person, the force of the wall on the ladder

The weight of the ladder and the weight of the person

Bars A and B are attached to a wall on the left and pulled with equal forces to the right. Bar B, with twice the radius, is stretched half as far as bar A. Which has the larger value of Young's modulus Y? YA > YB YA = YB YA < YB

YA > YB

When a tensile or compressive stress is applied to a rigid body and the stress is small enough such that the object returns to its original shape when the stress is removed, then the ratio of stress/strain is equal to __________. a value that depends on the strength of the stress the bulk modulus Young's modulus the shear modulus a value that depends on the amount of strain

Young's modulus

A very rigid material—one that stretches or compresses only slightly under large forces—has a large value of Tensile strength. Elastic limit. Density. Young's modulus.

Young's modulus.

The restoring force of three springs is measured as they are stretched. Which spring has the largest spring constant? a b c

a

A tensile stress is applied to a cylinder of length L0 and cross-sectional area A as shown in the figure. How do you calculate the strain on the cylinder that results from this applied stress? L sub 0 times delta L over A L sub 0 over delta L delta L over A Delta L delta L over L sub 0

delta L over L sub 0

When forces are exerted on an object, sometimes those forces will cause the object to be stretched, squeezed, or twisted. We define the deformation, which is the stretching, squeezing, or twisting of the object, as __________. shear strain tension compression stress

strain

When forces are exerted on an object, sometimes those forces will cause the object to be stretched, squeezed, or twisted. We define the strength of the force that might cause an object to be stretched, squeezed, or twisted as __________. deformation exertion stress strain

stress

An object is in equilibrium if t=net f=net Either A or B Both A and B

Both A and B

There are only two forces exerted on the simple meter stick shown in the figure (imagine it is floating in space, for example). The stick is otherwise free to move. The forces are exerted at theta is equal to 30 degrees measured from the meter stick. The net force exerted on the meter stick is __________. 50 N 21.7 N 25 N 12.5 N 0 N

0 N

There are only two forces exerted on the simple meter stick shown in the figure (imagine it is floating in space, for example). The rod is otherwise free to move. When measured with respect to an axis through the center of the meter stick, the net torque resulting from the forces exerted on the meter stick is _______. 38 N*m 76 N*m 17 N*m 0 N*m

0 N*m

What kind of stress is being applied to the cube in the figure? Tensile Shear Compressive Volume

Shear

What kind of stress is being applied to the cylinder in the figure? (arrows pointing out) Volume Shear Compressive Tensile

Tensile

A person with mass M stands on a ladder of mass m that leans against a frictionless vertical wall and makes an angle of 53° measured from the horizontal. The ladder does not slip on the horizontal surface due to a static frictional force between the ladder and the ground. Some of the forces exerted on the ladder can produce torques on the ladder. Using the contact point between the ladder and the ground as a reference, which force(s) exerted on the ladder produce counterclockwise torques? The weight of the ladder, the weight of the person, the static frictional force between the ladder and the ground. The weight of the ladder, the weight of the person, and the force of the wall on the ladder The force of the wall on the ladder and the static frictional force between the ladder and the ground. The force of the wall on the ladder The weight of the ladder and the weight of the person

The force of the wall on the ladder

A person with mass M stands on a ladder of mass m that leans against a frictionless vertical wall and makes an angle of 53° measured from the horizontal. The ladder does not slip on the horizontal surface due to a static frictional force between the ladder and the ground. For this ladder, which of the statements is true? The ladder is in translational equilibrium and rotational equilibrium but is not in static equilibrium. The ladder is in static equilibrium. The ladder is in translational equilibrium but not rotational equilibrium. The ladder is in rotational equilibrium but not translational equilibrium.

The ladder is in static equilibrium.

What is required for a rigid body to be in static equilibrium? The rigid body must exhibit no rotational motion but can exhibit translational motion. The rigid body must exhibit no translational motion and no rotational motion. The rigid body must exhibit no rotational motion and constant, non-zero translational motion. The rigid body must exhibit no translational motion but can exhibit rotational motion. The rigid body must exhibit no translational motion and constant, non-zero rotational motion.

The rigid body must exhibit no translational motion and no rotational motion.

There are only two forces exerted on the rod shown in the figure (imagine it is floating in space, for example). The rod is not uniform, with its center of mass shifted to the right, as indicated by point A in the figure. For the forces shown, which of the statements is true? The rod is in neither rotational nor translational equilibrium. The rod is in rotational equilibrium but not translational equilibrium. The rod is in static equilibrium. The rod is in translational equilibrium but not rotational equilibrium.

The rod is in neither rotational nor translational equilibrium.

There are only two forces exerted on the uniform rigid rod shown in the figure (imagine it is floating in space, for example). The rod is otherwise free to move. For the forces shown, which of the statements is true? The rod is in neither rotational nor translational equilibrium. The rod is in static equilibrium. The rod is in translational equilibrium but not rotational equilibrium. The rod is in rotational equilibrium but not translational equilibrium.

The rod is in rotational equilibrium but not translational equilibrium.

There are only two forces exerted on the uniform rigid rod shown in the figure (imagine it is floating in space, for example). The rod is otherwise free to move. For the forces shown, which of the statements is true? (25 on top left and bottom right) The rod is in rotational equilibrium but not translational equilibrium. The rod is in translational equilibrium but not rotational equilibrium. The rod is in neither rotational nor translational equilibrium. The rod is in static equilibrium.

The rod is in translational equilibrium but not rotational equilibrium.

What is required for a rigid body to be in translational equilibrium? There can only be one force exerted on the rigid body. The rigid body must exhibit no translational motion. The rigid body must exhibit no rotational motion. The sum of the forces exerted on the rigid body must be constant and non-zero. The sum of the forces exerted on the rigid body must be zero.

The sum of the forces exerted on the rigid body must be zero.

What is required for a rigid body to be in rotational equilibrium? The rigid body must exhibit no rotational motion. There can only be one torque due to all the forces exerted on the body. The sum of the torques due to all the forces exerted on the body must be constant and non-zero. The sum of the torques due to all the forces exerted on the body must be zero. The rigid body must exhibit no translational motion.

The sum of the torques due to all the forces exerted on the body must be zero.

When a volume stress is applied to a rigid body and the stress is small enough such that the object returns to its original shape when the stress is removed, then the ratio of stress/strain is equal to __________. the bulk modulus a value that depends on the amount of strain a value that depends on the strength of the stress Young's modulus the shear modulus

the bulk modulus

When a shear stress is applied to a rigid body and the stress is small enough such that the object returns to its original shape when the stress is removed, then the ratio of stress/strain is equal to __________. a value that depends on the strength of the stress the bulk modulus the shear modulus Young's modulus a value that depends on the amount of strain

the shear modulus