Susan is driving down the road at a constant speed. explain the forces
acting on the car and their relative magnitudes.

There is no forces acting on the car since it is in equilibrium. When a body is travelling at a constant speed, its net force is equal to zero. I hope my answer has come to your help. God bless and have a nice day ahead! Feel free to ask more questions.

answer: - b cells

explanation: -

there are many types of white blood cells present in our body. one such class of white blood cells are the lymphocytes. the b cells belong to the lymphocyte class of wbcs. the b cells perform their action against the pathogen by producing specialised proteins called as antibodies. these antibodies are produced as and when the b cells encounter pathogens in response to the antigens present on the surface of the pathogen. these antibodies bind to the antigens present on the pathogen and then, target them for destruction by other cells of the immune system.

so, the b cells mediate their action by identifying the antigens present on the surface of the pathogens and then producing antibodies in return to mediate its effect.