University:
Eastern Kentucky University
Course:
PHY 131 | College Physics I
Academic year:

2022
Views:

280

Pages:

2
Author:

sonalhava9qv

Chapter 6: *Friction (static) fs,max = μs N *Friction (Kinetic) fk = μk N *f = μN Chapter 7: *Kinetic Energy K = 1/2 mv^2 *Work done by Constant Force: W = Fd cosθ = F • d (When d is in same direction as F) Ex: What is work done by a person when he drops a pen? W = Wgravity + Wperson = 0 (INITIAL) Wgravity = mg(hINITIAL - hFINAL) Wperson = -Wgravity What is work done by a person when he lifts a box? W = Fd cosθ Wperson = Fperson • h Wtotal = Wg + Wperson = 0 Wg = -mghperson Wperson = mghperson *Work Done in Lifting & Lowering an object K_fi - K_i = W_g + W_ls, W_g = -W_ls *Spring Force F_s = -kx, k = constant *Work Done by a Spring Force W_s = 1/2 kx_i^2 - 1/2 kx_f^2 If x_i = 0 & x_f = x -> W_s = -1/2 kx^2 *Work Done by a Variable Force W = Integral from x_i to x_f of F_x dx, Integral from x_i to x_f of F_y dy, Integral from z_i to z_f of F_z dz *Work & Kinetic Energy ΔK = K_f - K_i = W (Work done by all forces combined) *Work done by Gravitational Force Wg = mgd cosθ Chapter 8: *Potential Energy U_g = mgh, h=height *Conservation of Energy U_i + K_i = U_f + K_f *Force is non-conservative E_2 - E_1 = W_n E = U + K K_2 + U_2 = (U_1 + K_1) + W_n (When dealing with friction and air resistance) Chapter 9: *Momentum P = mv, P = √2mK *Center of mass R_cm = (sum of m_i r_i) / (sum of m_i) M = sum of m_i V_cm = (sum of m_i v_i) / (sum of m_i) M_T = sum of m_i A_cm = (sum of m_i a_i) / (sum of m_i) M A_cm = sum of F_i *Conservation of Momentum ΔP_total = sum of F_ext Δt ΔP_total = (sum of F_ext) Δt