1. A piece of wood with uneven thickness, 2.4 meters in length. When the left end supports the ground, it needs 540 n to lift up the right end; when the right end supports the ground, it needs 360 n to lift up the left end. Find out (1) the gravity of the wood; (2) the distance from the center of the wood to the right end 2. AB is a straight board (excluding mass), O is the fulcrum, Ao = Bo = 0.65M, there are two balls a and B on the right side of the board, BC = 0.1M, m a = 0.3KG, M B = 0.2kg, the a end of the board is tied with a string, the board is in horizontal balance, if a ball moves at 0.13m/s, B ball moves at 0.1m/s to a at the same time, how long does it take AB to start to rotate around o? I also have the answers, the key is to solve the problem steps, but do not write a series. If you need to use ternary linear equations, please also write the steps of ternary linear equations, because I forgot the ternary linear equations. If you want to score, wait until you choose the best answer, because I'm afraid no one will answer, then the score will not come back

1. A piece of wood with uneven thickness, 2.4 meters in length. When the left end supports the ground, it needs 540 n to lift up the right end; when the right end supports the ground, it needs 360 n to lift up the left end. Find out (1) the gravity of the wood; (2) the distance from the center of the wood to the right end 2. AB is a straight board (excluding mass), O is the fulcrum, Ao = Bo = 0.65M, there are two balls a and B on the right side of the board, BC = 0.1M, m a = 0.3KG, M B = 0.2kg, the a end of the board is tied with a string, the board is in horizontal balance, if a ball moves at 0.13m/s, B ball moves at 0.1m/s to a at the same time, how long does it take AB to start to rotate around o? I also have the answers, the key is to solve the problem steps, but do not write a series. If you need to use ternary linear equations, please also write the steps of ternary linear equations, because I forgot the ternary linear equations. If you want to score, wait until you choose the best answer, because I'm afraid no one will answer, then the score will not come back

Do you see that the speed of a ball is faster than that of B ball? So the distance between the two balls will be longer and longer. When a ball moves to the left of the fulcrum, B ball is still on the right. When the ball rotates, there is only the force exerted by two balls. The rope is broken, so the force of the rope does not exist. Then you set T seconds later, and calculate the