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Physics 2053C – Fall 2001. Recap of Chaps. 1-7 Chapter 8 Rotational Motion. Newton’s 2 nd Law. Types of Forces: Gravity Normal Forces Friction Tension. The rate of change of momentum of a body is equal to the net force applied to it. Conservation of Energy.
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Physics 2053C – Fall 2001 Recap of Chaps. 1-7 Chapter 8 Rotational Motion Dr. Larry Dennis, FSU Department of Physics
Newton’s 2nd Law • Types of Forces: • Gravity • Normal Forces • Friction • Tension The rate of change of momentum of a body is equal to the net force applied to it.
Conservation of Energy • Total Energy Remains Constant. • Kinetic Energy K = ½mV2 • Potential Energy • U = mgh (gravity) • U = ½kX2 (spring) • Ki + Ui + Wnc = Kf + Uf
Motion in One Dimension • v = dx/dt • a = dv/dt • When a = constant: • v = vo + at • x = xo + vot + ½at2
Motion in Two Dimensions • vx = dx/dt and vy = dy/dt • ax = dvx/dt and ay = dvy/dt • Example: Free Fall (ay = -g ) • vy = voy - gt • y = yo + voyt - ½gt2 • vx = vox • x = xo + voxt
Circular Motion • a = v2/R • Force is towards the center of the circle. • Examples: Planetary Orbits
Conservation of Momentum When p= 0 (no net force) then: Momentum Before Collision = Momentum After Collision Mathematically this means: M1V1b + M2V2b = M1V1a + M2V2a
Rotational Motion • Uses all the above concepts and, • Rolling without slipping. • v = dx/dt • a = dv/dt • When a = constant: • v = vo + at • x = xo + vot + ½at2 • = d/dt • = d/dt • When a = constant: • = o + t • = o + ot + ½t2
F1 F2 R1 R2 Rotational Forces Torque • = I = RFsin or RF
Rotational Energy & Momentum • Kinetic Energy: K = ½I2 • Angular Momentum: L = I
Next Time • Chapter 8 – Rotational Motion. • Quiz on Chapter 7. • Please see me with any questions or comments. See you on Wednesday.