Exam #4 General Physics I (PHY 1123)

Angular Motion and Displacement

• Angular displacement is expressed in radians.

Momentum

• SI unit of momentum is N-s.

Angular Velocity and Acceleration

• Angular velocity is expressed in radians per second.

• Angular acceleration is expressed in radians per second squared.

Conservation of Momentum

• When mass is added to a moving freight car, its velocity decreases:
  

• Earth travels an arc length of 2.4 × 10^{11} m in three months.

Kinetic Energy

• Kinetic energy in terms of momentum: KE = p^2/(2m)

Distance and Revolutions

• The tip of the second hand sweeps through 7.1 m in 3 minutes and 45 seconds.

Linear Speed

• Linear speed of a point on a rotating wheel is 0.31 m/s.

Collisions

• A light beach ball colliding with a heavy exercise ball will rebound with approximately the same speed, 6.0 m/s.

Centripetal Acceleration

• Centripetal acceleration calculation: a_c = v^2/r

• The centripetal acceleration of a point on a bicycle wheel is 183 m/s^2

Momentum Magnitude

• Magnitude of momentum: p = mv

• The magnitude of the ferryboat's momentum is 2.4 × 10^4 kg·m/s

Centripetal Force

• Centripetal acceleration calculation: a_c = v^2/r

• The centripetal acceleration of the car is 8.0 m/s^2

Torque

• The force required to tighten bolts is 380 N.

Change in Momentum

• The change in momentum of the tennis ball is 1.8 kg·m/s

Angular Acceleration

• The angular acceleration experienced by the wheel is 1.17 rad/s^2

Average Force

• The magnitude of the average force the bat exerted is 800 N.

Rod Angular Acceleration

• The angular acceleration as it is released is 3.68 rad/s^2

Center of Mass

• The center of mass on the x-axis is +15.0 m.

Moment of Inertia

• The moment of inertia of the wheel is 12.5 kg·m^2$$