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Intermediate
Mathematical
GQ

A cat chases a mouse across a \(1.0 \, \text{m}\) high table. The mouse steps out of the way, and the cat slides off the table and strikes the floor \(2.2 \, \text{m}\) from the edge of the table. When the cat slid off the table, what was its speed?

Advanced
Conceptual
MCQ

In which one of the following circumstances does the principle of conservation of mechanical energy apply, even though a nonconservative force acts on the moving object?

Advanced
Mathematical
FRQ

A \( 1.5 \; \text{kg} \) mass attached to a spring with a force constant of \( 20.0 \; \text{N/m} \) oscillates on a horizontal, frictionless track. At \( t = 0 \), the mass is released from rest at \( x = 10.0 \; \text{cm} \). (That is, the spring is stretched by \( 10.00 \; \text{cm} \).)

Beginner
Conceptual
MCQ

For an object oscillating in SHM, what is the relationship between its displacement, velocity, and acceleration graphs as a function of time?

Advanced
Proportional Analysis
MCQ

A circus cannon fires an acrobat into the air at an angle of \( 45^\circ \) above the horizontal, and the acrobat reaches a maximum height \( y \) above her original launch height. The cannon is now aimed so that it fires straight up, at an identical speed, into the air at an angle of \( 90^\circ \) to the horizontal. In terms of \( y \), what is the acrobat’s new maximum height?

Advanced
Mathematical
FRQ

Three blocks of masses \(m_3 = 1.0 \, \text{kg}\), \(m_2 = 2.0 \, \text{kg}\), and \(m_1 = 4.0 \, \text{kg}\) are connected by massless strings, one of which passes over a frictionless pulley of negligible mass, as shown above.

Beginner
Conceptual
GQ

Two students hold a large bed sheet vertically between them. A third student, who happens to be the star pitcher on the school baseball team, throws a raw egg at the center of the sheet. Explain why the egg does not break when it hits the sheet, regardless of its initial speed.

Advanced
Conceptual
MCQ

A kickball is rolled by the pitcher at a speed of 10 m/s and it is kicked by another student. The kickball deforms a little during the kick, and then rebounds with a velocity of 15 m/s as its shape restores to a perfect sphere. Select all that must be true about the kickball and the kicking foot system.

Beginner
Conceptual
MCQ

A solid metal bar is at rest on a horizontal frictionless surface. It is free to rotate about a vertical axis at the left end. The figures below show forces of different magnitudes that are exerted on the bar at different locations. In which case does the bar’s angular speed about the axis increase at the fastest rate?

Beginner
Mathematical
GQ

Two balls have their centers \( 2.0 \) \( \text{m} \) apart. One ball has a mass of \( 8.0 \) \( \text{kg} \). The other has a mass of \( 6.0 \) \( \text{kg} \). What is the gravitational force between them?

Intermediate
Conceptual
MCQ

The motions of a car and a truck along a straight road are represented by the velocity–time graphs in the figure. The two vehicles are initially alongside each other at time \(t = 0\). At time \(T\), what is true of the distances traveled by the vehicles since time \(t = 0\)?

Intermediate
Conceptual
MCQ

A solid sphere, solid cylinder, and a hollow pipe all have equal masses and radii. If the three of them are released simultaneously from the top of an inclined plane and do not slip, which one will reach the bottom first?

Intermediate
Mathematical
MCQ

A ball falls straight down through the air under the influence of gravity. There is a retarding force \(F\) on the ball with magnitude given by \(F=bv\), where \(v\) is the speed of the ball and \(b\) is a positive constant. The ball reaches a terminal velocity after a time \(t\). The magnitude of the acceleration at time \(t/2\) is

Intermediate
Mathematical
GQ

A 45 kg crate accelerates at 1.65 m/s2 when pulled by a rope with a force of 200 N. Find the angle the rope is pulled at. Friction is negligible.

Intermediate
Conceptual
MCQ

A rocket explodes into two fragments, one \(25\) times heavier than the other. The change in momentum of the lighter fragment is

Intermediate
Conceptual
MCQ

A merry-go-round spins freely when Diego moves quickly to the center along a radius of the merry-go-round. As he does this, it is true to say that

Advanced
Conceptual
MCQ

A whiffle ball is tossed straight up, reaches a highest point, and falls back down. Air resistance is not negligible. Which of the following statements are true?

  1. The ball’s speed is zero at the highest point.
  2. The ball’s acceleration is zero at the highest point.
  3. The ball takes a shorter time to travel up to the highest point than to fall back down.
Intermediate
Mathematical
GQ

A \(350\ \text{g}\) ball is attached to the end of a thin, uniform rod of mass \(500\ \text{g}\) and length \(1.2\ \text{m}\). The system is rotated in a horizontal circle about the opposite end of the rod. Calculate the moment of inertia of the system about the axis of rotation. Hint: the moment of inertia of a thin rod about the end of the rod is \(I = \tfrac{1}{3} m L^2\).

Intermediate
Conceptual
GQ

Suppose you are a passenger traveling in car along a road that bends to the left. Why will you feel like you are being thrown against the door. What causes this force?

Intermediate
Conceptual
MCQ

Two objects labeled K and L have equal mass but densities \( 0.95D_o \) and \( D_o \), respectively. Each of these objects floats after being thrown into a deep swimming pool. Which is true about the buoyant forces acting on these objects?

Advanced
Mathematical
GQ

The ultracentrifuge is an important tool for separating and analyzing proteins. Because of the enormous centripetal accelerations, the centrifuge must be carefully balanced, with each sample matched by a sample of identical mass on the opposite side. Any difference in the masses of opposing samples creates a net force on the shaft of the rotor, potentially leading to a catastrophic failure of the apparatus. Suppose a scientist makes a slight error in sample preparation and one sample has a mass \( 10 \) \( \text{mg} \) larger than the opposing sample.

 

If the samples are \( 12 \) \( \text{cm} \) from the axis of the rotor and the ultracentrifuge spins at \( 60000 \) \( \text{rpm} \), what is the magnitude of the net force on the rotor due to the unbalanced samples?

Intermediate
Conceptual
FRQ

A beaker weighing \( 2.0 \) \( \text{N} \) is filled with \( 5.0 \times 10^{-3} \) \( \text{m}^3 \) of water. A rubber ball weighing \( 3.0 \) \( \text{N} \) is held entirely underwater by a massless string attached to the bottom of the beaker, as represented in the figure above. The tension in the string is \( 4.0 \) \( \text{N} \). The water fills the beaker to a depth of \( 0.20 \) \( \text{m} \). Water has a density of \( 1000 \) \( \text{kg/m}^3 \). The effects of atmospheric pressure may be neglected.

Intermediate
Mathematical
FRQ

Initially, a ball has an angular velocity of \( 5.0 \) \( \text{rad/s} \) counterclockwise. Some time later, after rotating through a total angle of \( 5.5 \) \( \text{radians} \), the ball has an angular velocity of \( 1.5 \) \( \text{rad/s} \) clockwise.

Beginner
Conceptual
MCQ

A point P is at a distance \( R \) from the axis of rotation of a rigid body whose angular velocity and angular acceleration are \( \omega \) and \( \alpha \) respectively. The linear speed, centripetal acceleration, and tangential acceleration of the point can be expressed as:

Linear speed Centripetal acceleration Tangential acceleration
\( (a) \) \( R\omega \) \( R\omega^{2} \) \( R\alpha \)
\( (b) \) \( R\omega \) \( R\alpha \) \( R\omega^{2} \)
\( (c) \) \( R\omega^{2} \) \( R\alpha \) \( R\omega \)
\( (d) \) \( R\omega \) \( R\omega^{2} \) \( R\omega \)
\( (e) \) \( R\omega^{2} \) \( R\alpha \) \( R\omega^{2} \)

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