An 80cm long pendulum with a .60kg bob is released from rest at an initial angle of Theta with the vertical. At the bottom of the swing, the speed of the bob is 2.8m/s. a)what is Theta? b)What angle does the pendulum makes with the vertical when the speed of the bob is 1.4m/s? Revelant equation: Ui + Ki = Uf + Kf I converted 80cm to .8m. mgh + 0 = 0 + 1/2 m v^2 .60kg * 9.81 m/s * h = 1/2 .60kg * (2.8m/s)^2 I need to solve for h which is .3995922528 approx .4m Length is .8m h = L - Lcos Theta .4m = .8m - Lcos Theta .5 = Cos Theta Cos^-1 = 60 Is this correct? and Part b is the same procedure correct?