cos 30 = adj/hyp
cos 30 = adj/1.4
1.21m = adj
1.4 - 1.21 = 0.19m off the ground
cos 20 = adj/hyp
cos 20 = adj/1.4
1.32m = adj
1.4 - 1.32 = 0.08m off the ground
mgh = 0.5mv2 + mgh
gh = 0.5v2 + gh
9.8(0.19) - 9.8(0.08) = 0.5v2
1.47 m/s = v
Although it's close, it's about 0.05 m/s off from the...
Homework Statement
To make a pendulum, a 300g ball is attached to one end of a string that has a length of 1.4m and negligible mass. (The other end of the string is fixed) The ball is pulled to one side until the string makes a 30 degree angle with the vertical, then (with the string taut) the...