Physics

Front 1

When a rigid body rotates about a fixed axis all the points in the body have the same angular displacement.

Back 1

True

Front 2

When a rigid body rotates about a fixed axis all the points in the body have the same linear displacement.

Back 2

False

Front 3

When a rigid body rotates about a fixed axis all the points in the body have the same angular speed.

Back 3

True

Front 4

When a rigid body rotates about a fixed axis all the points in the body have the same tangential speed.

Back 4

False

Front 5

Two children are riding on a merry-go-round. Child A is at a greater distance from the axis of rotation than child B. Which child has the larger linear displacement?

Back 5

Child A

Front 6

Two children are riding on a merry-go-round. Child A is at a greater distance from the axis of rotation than child B. Which child has the larger angular speed?

Back 6

They have the same non-zero angular speed

Front 7

Two children are riding on a merry-go-round. Child A is at a greater distance from the axis of rotation than child B. Which child has the larger centripetal acceleration?

Back 7

Child A

Front 8

Does the centripetal force acting on an object do work on the object?

Back 8

no, because the forve and the displacement of the object are perpendicular

Front 9

Two horizontal curves on a bobsled run are banked at the same angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for the smaller radius curve is V. Therefore, the safe speed on the larger radius curve is

Back 9

1.4 V

Front 10

A race car, traveling at a constant speed of 50 m/s, drives around a circular track of radius 250 m. What angular acceleration does it experience?

Back 10

zero

Front 11

A spherically symmetric planet has four times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12. N on the surface of the Earth, how much would it weigh on the surface of this planet?

Back 11

12 N

Front 12

The speed of Halley's comet, while traveling in its elliptical orbit around the sun,

Back 12

increases as it nears the sun

Front 13

Kepler's discovery that T^2/ r^3 = K applies

Back 13

to ellpitical orbits where r is the average distance

Front 14

James moves in a circular path (radius 15.0 m) with a speed of 60.0 m/s. His ANGULAR VELOCITY is

Back 14

120/pi rpm

Front 15

A pulsar (a rotating neutron star) emits pulses at a frequency of 0.40 kHz. The period of its rotation is

Back 15

2.5 m

Front 16

A flywheel, of radius 1 m, is spinning with a constant angular velocity of 2 rad/s. What is the centripetal acceleration of a point on the wheel's rim?

Back 16

4m/s^2

Front 17

What is the centripetal acceleration of a point on the perimeter of a bicycle wheel of diameter 70. cm when the bike is moving 8.0 m/s?

Back 17

1.8 x 10 ^2 m

Front 18

A space station of diameter 40. meters is turning about its axis at a constant rate. What is the period of revolution of the space station if the outer rim experiences an acceleration of 2.5 m/?

Back 18

18 s

Front 19

A car traveling 20 m/s rounds an 80 m radius horizontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume the same coefficient of friction between the car's tires and each road surface.)

Back 19

40 m/s

Front 20

The flywheel of a machine is rotating at 126 rad/s. Through what angle will the wheel be displaced from its original position after 6.0 s?

Back 20

0.32 revolutions

Front 21

When a rigid body rotates about a fixed axis all the points in the body have the same linear displacement

Back 21

False

Front 22

When a rigid body rotates about a fixed axis all the points in the body have the same angular speed.

Back 22

True

Front 23

Unbalanced torques produce rotational accelerations, and balanced torques produce rotational equilibrium.

Back 23

True

Front 24

If an object is in unstable equilibrium, any small displacement results in a restoring force or torque, which tends to return the object to its original equilibrium position.

Back 24

False

Front 25

An object in motion with constant speed along a straight line can never have nonzero angular momentum.

Back 25

False

Front 26

Consider a rigid body that is rotating. Which of the following is an accurate statement?

Back 26

All points on the body are moving with the same angular velocity

Front 27

A pencil balanced on its tip such that it does not move

Back 27

Is in unstable equilibrium

Front 28

If a constant net torque is applied to an object, that object will

Back 28

rotate with constant angular acceleration

Front 29

Two equal forces are applied to a door. The first force is applied at the midpoint of the door; the second force is applied at the doorknob. Both forces are applied perpendicular to the door. Which force exerts the greater torque?

Back 29

The second at the doorknob

Front 30

Two equal forces are applied to a door at the doorknob. The first force is applied perpendicular to the door; the second force is applied at 30° to the plane of the door. Which force exerts the greater torque?

Back 30

The first applied perpendicular to the door

Front 31

Five forces act on a massless rod free to pivot at point P, as shown in Fig. 8-1. Which force is producing a counter-clockwise torque about point P?

Back 31

C

Front 32

A heavy boy and a lightweight girl are balanced on a massless seesaw. If they both move forward so that they are one-half their original distance from the pivot point, what will happen to the seesaw?

Back 32

Nothing the seesaw will be be balanced

Front 33

A heavy seesaw is out of balance. A lightweight girl sits on the end that is tilted downward, and a heavy boy sits on the other side so that the seesaw now balances. If the boy and girl both move forward so that they are one-half their original distance from the pivot point, what will happen to the seesaw?

Back 33

The side the girl is sitting on will once again tilt downward

Front 34

Consider a solid object which is subjected to a net torque. That object will experience which of the following?

Back 34

An angular acceleration

Front 35

Consider two uniform solid spheres where both have the same diameter, but one has twice the mass of the other. The ratio of the larger moment of inertia to that of the smaller moment of inertia is

Back 35

2

Front 36

A solid cylinder and a hollow cylinder have the same mass and the same radius. Which statement is true concerning their moment of inertia about an axis through the exact center of the flat surfaces?

Back 36

The hollow cylinder has the greater moment of inertia

Front 37

A boy and a girl are riding on a merry-go-round that is turning. The boy is twice as far as the girl from the merry-go-round's center. If the boy and girl are of equal mass, which statement is true about the boy's moment of inertia with respect to the axis of rotation?

Back 37

His moment of inertia is 4 times the girls

Front 38

A ball, solid cylinder, and a hollow pipe all have equal masses and radii. If the three are released simultaneously at the top of an inclined plane, which will reach the bottom first?

Back 38

Ball

Front 39

An ice skater performs a pirouette (a fast spin) by pulling in his outstretched arms close to his body. What happens to his angular momentum about the axis of rotation?

Back 39

It does not change

Front 40

An ice skater performs a pirouette (a fast spin) by pulling in his outstretched arms close to his body. What happens to his moment of inertia about the axis of rotation?

Back 40

It decreases

Front 41

An ice skater performs a pirouette (a fast spin) by pulling in his outstretched arms close to his body. What happens to his rotational kinetic energy about the axis of rotation?

Back 41

It increases

Front 42

A seesaw made of a plank of mass 10.0 kg and length 3.00 m is balanced on a fulcrum 1.00 m from one end of the plank. A 20.0-kg mass rests on the end of the plank nearest the fulcrum. What mass must be on the other end if the plank remains balanced?

Back 42

7.50 kg

Front 43

50) A thin hoop with a radius of 10 cm and a mass of 3.0 kg is rotating about its center with an angular speed of 3.5 rad/s. What is its kinetic energy?

Back 43

0.18 J

Front 44

The moment of inertia of a solid cylinder about its axis is given by 0.5M. If this cylinder rolls without slipping, the ratio of its rotational kinetic energy to its translational kinetic energy is

Back 44

1:2

Front 45

An ice skater has a moment of inertia of 5.0 kg∙m2 when her arms are outstretched. At this time she is spinning at 3.0 revolutions per second (rps). If she pulls in her arms and decreases her moment of inertia to 2.0 kg∙m2, how fast will she be spinning?

Back 45

7.5 rps

Front 46

If an external pressure is applied to a confined fluid, the pressure at every point within the fluid increases by that amount.

Back 46

True

Front 47

An object completely submerged in water must either rise or fall.

Back 47

False

Front 48

Stress is

Back 48

Applied force per cross sectional area

Front 49

Strain is

Back 49

The ratio of the change in length to the original length

Front 50

Which one of the following would be expected to have the smallest BULK MODULUS?

Back 50

helium vapor

Front 51

The slope of the straight line shown on the graph in Fig. 9-1 is called the

Back 51

Youngs modulus

Front 52

The weight that will cause a wire of diameter d to stretch a given distance, for a fixed length of wire, is

Back 52

Proportional to d^2

Front 53

When you are scuba diving, the pressure on your face plate

Back 53

depends only on your depth and not on how you are oriented

Front 54

A spherical inflated balloon is submerged in a pool of water. If it is further inflated so that its radius doubles, how is the buoyant force affected?

Back 54

4 times larger

Front 55

A submarine rests on the sea bottom. The normal force exerted upon the sub by the sea-floor is equal to

Back 55

the weight of the sub less (minus) the weight of the displaced water

Front 56

The pressure differential across a wing cross section due to the difference in air flow is explained by

Back 56

Bernoulli's equation

Front 57

A mass of 1000 kg hangs at the end of a steel rod 5.0 m in length. The diameter of the rod is 0.80 cm and Young's modulus for the rod is 210,000 MN/m2. What is the elongation of the rod?

Back 57

0.46 cm

Front 58

A 0.600-mm diameter wire stretches 0.5% of its length when it is stretched with a tension of 20 N. What is the Young's modulus of this wire?

Back 58

1.41 x 10^10 N/m ^2

Front 59

A cable is 100-m long and has a cross-sectional area of 1 mm2. A 1000-N force is applied to stretch the cable. The elastic modulus for the cable is 1.0 × 1011 N/m2. How far does it stretch?

Back 59

1.0 m

Front 60

A copper wire is found to break when subjected to minimum tension of 36. N. If the wire diameter were half as great, we would expect the wire to break when subjected to a minimum tension of

Back 60

9.0 N

Front 61

Instead of cables, a hydraulic lift raises an elevator weighing 2.5 kiloNewtons. The input piston has a 2.0 cm diameter and the lift piston has a 28. cm diameter (See Fig. 9-3). What minimum force must be applied to the input piston?

Back 61

13 N

Front 62

A 13000 N vehicle is to be lifted by a 25 cm diameter hydraulic piston. What force needs to be applied to a 5.0 cm diameter piston to accomplish this?

Back 62

520 N

Front 63

A rock is suspended from a scale reads 20.0 N. A beaker of water is raised up so the rock is totally submerged in the water. The scale now reads 12.5 N. What is the density of the rock?

Back 63

2.67 x 10 ^3 kg/m^3

Front 64

A ship that weighs 10,000 tons (mass 10 million kg) must displace what volume of fresh water in order to float

Back 64

10 ^4m ^ 3

Front 65

An incompressible fluid flows steadily through a pipe that has a change in diameter. The fluid speed at a location where the pipe diameter is is What is the fluid speed at a location where the diameter has narrowed to

Back 65

5.12

Front 66

A 3.00-m long tube with circular crosssection tapers from a diameter of 10.0 cm at one end down to 4.00 cm at the other end. If an incompressible fluid flows irrotationally through the tube at a speed of 2.00 m/s at the 10.0 cm end, what is the speed of the flow at the 4.00 cm diameter end?

Back 66

12.5 m/s

Front 67

Air is flowing through a rocket nozzle. Inside the rocket the air has a density of 5.25 kg/m3 and a speed of 1.20 m/s. The interior diameter of the rocket is 15.0 cm. At the nozzle exit, the diameter is 2.50 cm and the density is 1.29 kg/m3. What is the speed of the air when it leaves the nozzle?

Back 67

176 m/s

Front 68

When a rigid body rotates about a fixed axis all the points in the body have the same centripetal acceleration.

Back 68

False