Zusammenfassung der Ressource
Exam 2
- CH 5: Circular Motion and Gravitation
- period of motion =T= (2 pi r)/v
- centripetal acceleration = ac = (v^2)/r
- spinning rate = w = v/r
- used in many cases
- planet orbits, satellite orbits
- theme park ride: turns, loops and hills
- CH 6: Work and Energy
- Work= Force multiplied by the difference of x multiplied by cos of the angle
- Work is measure in Joules (J)
- W= Fxcos(angle)
- Energy: Kinetic and Potential
- Kinetic Energy (KE)= 1/2 mv^2
- Potential Energy (PE)= mgh
- Mechanical Energy= mgh + 1/2 mv^2
- E1 = E2
- KEi + PEi = KEf + PEf
- CH 8: Rotational Motion
Anlagen:
- Describing rotational motion
- Rotational Quantities
- Angular position = theta
- theta = (s/r) where s is arc length, r is radius
- Angular velocity = lowercase omega (fancy w)
- omega = theta/time
- Angular acceleration = alpha
- alpha = omega/time
- Radians
- 360 degrees = 2(pi) rad
- Torque and Newton's Laws for rotational motion
- torque = Force * radius
- sigma torque = I * alpha
- moment of inertia = I = dependent upon object and shape
- Newton's second law for rotational motion
- Rotational Equilibrium
- total torque = 0
- Rotational Dynamics
- delta theta = (angular velocity)(delta time) + 1/2(alpha)(delta time ^2)
- final angular velocity = (initial ang velocity) + (alpha)(delta time)
- (ang velocity final ^2) = (ang velocity initial ^2) + 2(alpha)(delta theta)
- Combined Rotational and Translational Motion
- Arises in many cases
- a rolling wheel
- motion of a baseball bat
- Rolling Motion
- angular v * R = v = 2(pi)R / T
- a = alpha * R
- base ball bat scenario
- more complex than rolling motion
- involves linear and rotational:
- quantities, dynamics, and center of mass
- Chapter 7 - Momentum, impulse, and collisions
- Momentum
- Momentum(P) = mass x velocity
- Momentum is conserved during collisions
- Impulse
- Impulse is the change in time multiplied by the force in question. This is the same as the change in momentum.
- Collisions
- Elastic collisions
- Kinetic energy is conserved
- KE1f+KE2f = KEi1+KEi2
- momentum is conserved
- Inelastic collisions
- Kinetic energy is not conserved
- KE1f+KE2f not equal to KE1i+KE2i
- Vf = (m1v1i + m2v2i)/(m1+m2)
- momentum is conserved
- Kinetic energy = 1/2 mv
- completely inelastic collisions
- objects stick together after collisions
- momentum still conserved