In endothermic chemical reaction, the energy lost from the surroundings must be what compared to the energy gained by the reaction?

The cement bag shown in the figure has a mass of 50 kg and the small pulley has a mass of 2 kg. if the cement bag is pulled upwards with an acceleration of 2 m/s^2, find the force f pulling the rope.

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j? 1. write the equation 2.list out your known variables 3.plug the numbers into the equations 4.solve 5.write your solution statement that includes initial energy and final

During the experiment if you could triple the breakaway magnetic force with all other quantities left unchanged, what is the new value for the critical velocity if it was v0 (initial velocity), initially? (b) now if you halved the radius with all other quantities left unchanged, what is the new critical velocity if it was v0 (initial velocity), initially? (c) if during the experiment, critical velocity quadrupled with all other quantities left unchanged, what is the new breakaway force if its magnitude was initially f0,?