# Physics HELP!!!!

posted by
**Michael**
.

A small ball of mass m=0.60 kg hangs from a massless string of length l= 1.2 m. The ball travels in a vertical circle and its speed at the bottom is v0= 6.0 m/s (see figure). Neglect all friction and air drag, and use g=10 m/s2 for the gravitational acceleration. The ball is so small that we can approximate it as a point.

(a) Find the speed of the ball (in m/s) when the string is at α= 80∘.

v(α= 80∘)= 4.02889 (i got this one)

(b) What is the tension in the string (in Newton) when it is at α= 80∘?

T(α= 80∘)=

(c) The string of the pendulum is cut when it is at α= 80∘. First, we want to neglect all air drag during the trajectory of the ball. What is the maximal height h (in meters) the ball reaches above its point of release? What time tup (in s) does it take the ball to reach the highest point from the instant the string is cut? What time tdn (in s) does it take the ball to go from the highest point back to the altitude it was released from the string?

h(α= 80∘)=

tup(α= 80∘)=

tdn(α= 80∘)=