A painter and his helper are standing on a scaffold. The painter weighs 400 newtons. The helper weighs 300 newtons. The tension in a rope A is 925 newtons. The tension in rope B is 825 newtons. What Is the weight of the board?

A980-kg sports car collides into the rear end of a 2300-kg suv stopped at a red light. the bumpers lock, the brakes are locked, and the two cars skid forward 2.6m before stopping.the police officer, estimating the coefficient of kinetic friction between tires and road to be 0.80, calculates the speed of the sports car at impact. what was that speed?