They dont work because you crushed them duh
The fluid that is being passed through the syringe and needle is incompressible, which means that it will transmit pressure equally. Therefore, the pressure on the plunger will be equivalent to the pressure on the needle. We also know that:
Pressure = Force / Area
Pressure on plunger = 4 / (π*(0.012/2)²)
Pressure on plunger = 35.4 kPa
Pressure on needle = 35.4 kPa
35.4 kPa = F / (4 / (π*(0.0025/2)²)
F = 0.17 N
The force on the needle is 0.17 N
Carbon is the answer. IF oxygen were on the list it would also be correct but for this its Carbon<span />
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