Use the right hand rules to show that the force between the two loops in Figure 22.55 is attractive if the currents are in the same direction and repulsive if they are in opposite directions. Is this consistent with like poles of the loops repelling and unlike poles of the loops attracting? Draw sketches to justify your answers.

Day 12 2/1/2016 Topics for Midterm fluids of all kinds, not differential equations harmonic oscillator, up to damping simple harmonic motion some problems with damping and resonance after exam Read 15.1, 15.2, 15.4 Waves y(x, t) = Asin(kx wt) displacement amplitude of displacement t = 0 y(x, t) = Asin(kx) x = 0 y(x=0, t) = Asin(wt) = Asin(wt) y(x, t=0) = y(x + λ, t=0) Asin(kx) = Asin[k(x+λ)] kλ = 2π 2π The wave number k = γ Asin(wt) = Asin[w(t+T)] wT = 2π → w = 2π = rad angular frequency T s frequency f → f = T1 Ex. vw= 0.5 cm/s A = 1cm T = 8s λ = 4cm k = π rad ω = 2π = π rad 2 cm T 4 cm y(x, t) = 1 cm sin ( π rax − π rat) 2 cm 4 s verify, does 4(x = 0, t = 0) = graphs says no! Initial Phase Phase φ = kx − ωt y(x,t) = Asin(φ + φ )o π π π sin(kx ωt+ )2= sin(φ)cos( ) + c2s(φ)sin( ) 2 Ex. y(x, t) = Asin(kx wt) = Asin(x t)k = 1, w = 1 t = 0 y(x, 0) = Asinx t = π y(x, ) = Asin(x ) = Asinxcos( ) Acosxsin( ) π 2 2 2 2 2 y(x, ) = Acosx 2 y = Asin(kx wt)