maniacp08
Oct28-08, 03:29 PM
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?
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?