What is the acceleration of a 100 kg object that experience a net force of -10N?

Explain vector addition, triangle method and parallelogram method

Truck traveling west on the highway experiences an acceleration to the east. what could be the cause of this acceleration

10 newton object is placed 3 meters from the fulcrum. at what distance on the other side would you need to place a 15 newton object to balance the lever? show your work!