Two children push on opposite sides of a door during play. Both push horizontally and perpendicular to the door. One child pushes with a force of 30 N at a distance of 60 cm from the hinges, and the second child pushes at a distance of 45 cm. Assume friction is negligible. The force must the second child exert to keep the door from moving is (A) 40 N (B) 30 N (C) 60 N (D) Cannot be determined

Asteam power plant operates on an ideal reheat rankine cycle between the pressure limits of 15 mpa and 10 kpa. the mass flow rate of steam through the cycle is 12 kg/s. steam enters both stages of the turbine at 500°c. if the moisture content of the steam at the exit of the low-pressure turbine is not to exceed 10 percent, determine (a) the pressure at which reheating takes place, (b) the total rate of heat input in the boiler, and (c) the thermal efficiency of the cycle. also, show the cycle on a t-s diagram with respect to the saturation lines. (2.15 mpa; 45.0 mw; 42.6%)

Iwill give 30 points to whoever answers ! what is the formula for actual mechanical advantage and ideal mechanical advantage?

What kind of simple machine is a catapult?