Is polystyrene a mixture or pure substance

Polystyrene is a mixture substance. Polystyrene is a flexible plastic used to cater to different products ranging from food tupperwares to appliances. It is created by putting together, or polymerizing, styrene (building-block chemical and naturally existed in foods like strawberries, cinnamon, coffee and beef). When hard, it is used to make food packaging and laboratory equipments. When put together with different colors, additives or even plastics, it helps in making electronics, automobile parts, toys, appliances, gardening pots and equipment and many more

Ithink it’s 98 because jajajjajansmsmjs

I'm having some difficulty seeing the diagram clearly.but the question says there's a net inward force on the object.so we know right away,  from newton's 2nd law of motion, thatthat baby is accelerating.  it doesn't even matter which way thenet force is pointing.  if there's any net force, then either theobject's speed or else its direction must be changing.