About Pelton turbine

The exit diameter of the nozzle is 80 mm. The wheel has a diameter of 2 m at the pitch circle. The buckets can be assumed to deflect the water jet by 90 degrees, when running. Ignore all losses.
The velocity of the jet at nozzle exit
The mass flow rate out of the nozzle
The hydraulic power output of the nozzle
The force applied by the jet on the bucket
The torque applied by the jet to the wheel
The efficiency of the turbine, if it is running at 300 rpm
I need answers with explanations about the formulas.