Dooley

Start by translating the question into "physics language:" "If the rock is thrown up at time t=0, what is the time, t1, when the rock hits the water. You can use the usual equation x = 1/2 a t^2 + v0 t + x0. v0 = 21 m/sec and x0=41 meters (taking x=0at th...

x = 1/2 a t^2 + v0 t + x0 and v = at + v0 (a)needs no translation, but some work: with v=12m/s, solve the velocity equation for the special time t (call it t) when the ball is at the window (in terms of 12m/sec and v0). Don't lose your nerve. Now plug tha...

A procedural error would be to light it with a blowtorch and blow some of the liquid wax off onto the floor. If the scale is incorrectly calibrated it will give you a systematic error. You would notice random errors if you did many trials and got a scatte...