The product structure diagram shows the number of different components required at each level to produce one unit of the final product P. If there are 50 units of on hand inventory of component A, the number of additional units of component A needed to produce 10 units of product P is _________ (in integer).

A square threaded screw is used to lift a load W by applying a force F. Efficiency of square threaded screw is expressed as

A CNC worktable is driven in a linear direction by a lead screw connected directly to a stepper motor. The pitch of the lead screw is 5 mm. The stepper motor completes one full revolution upon receiving 600 pulses. If the worktable speed is 5 m/minute and there is no missed pulse, then the pulse rate being received by the stepper motor is

The type of fit between a mating shaft of diameter $25.0^{\begin{matrix} +0.010 \\\ -0.010 \end{matrix}}$ mm and a hole of diameter $25.0^{\begin{matrix} +0.015 \\\ -0.015 \end{matrix}}$ is ______.