The tip of a sewing needle is sharp because the area under the pointed end of the sharp needle is very small. Pressure exerted by a sharp needle is more on the cloth and can pierce easily through the cloth.
Why are needles made pointed?
Needle is made pointed because pressure exerted at that point is more. Pointed part has less area. So the pressure is more at that point. That makes use of needle easy.
Why does a knife have a sharp edge and a needle has a sharp tip?
Answer Expert Verified
The edge of a knife or the tip of a needle has a small area of contact. That is why a sharp needle is able to puncture the skin when a small force is exerted, but applying the same force with a finger does not.
What is sharp needle?
The sharp needle (or ‘sharp’) is a type of needle used for general hand sewing, including decorative needlework. The sharp needle has a sharp point, rounded eye and is of medium length (generally between 4 and 5 cm). It is sometimes also called an appliqué needle.
Why do needles and pins have pointed tips?
Answer Expert Verified
Sewing needles and all pins have sharp pointed tips to enable better piercing and at the same time cause minimum damage to the fabric or fibre of the cloth or paper, both of which have cellulose as the basic material of construction.
Why cutting knife is sharp explain?
A sharp knife cut objects better because due to its very thin edge, the force of our hand falls over a very small area of the object producing a large pressure and this large pressure cuts the object easily. While a blunt knife has a thicker edge. … This lesser pressure cuts the object with difficulty.
Why does a knife have a sharp edge?
We can say that for an equal amount of force applied, the pressure will be more by the body with a smaller surface area as compared to a body with larger surface area. … Thus, knives and blades have sharp edges because they provide less surface area relating to more Pressure.
Why is the cutting edge of a knife so thin?
As Area decreases, Pressure Increases. P is inversely proportional to Area. Thats why cutting edge of knife is made with very less Area.
What tests are done after a needlestick?
Laboratory studies in exposed individuals/health care worker include the following: Hepatitis B surface antibody. HIV testing at time of incident and again at 6 weeks, 3 months, and 6 months. Hepatitis C antibody at time of incident and again at 2 weeks, 4 weeks, and 8 weeks.
What happens if you touch a used needle?
If a person sustains an injury from a discarded used needle in the community it usually causes a great degree of anxiety and distress. The main fear is that the injury caused by the discarded used needle may result in infection with HIV or hepatitis. The risk of acquiring these infections is extremely low.
What are the chances of getting a disease from a needlestick?
Your chances of catching a disease from a single needle stick are usually very low. About 1 out of 300 health care workers accidentally stuck with a needle from someone with HIV get infected. But for hepatitis B, the odds can be as high as nearly 1 in 3 if the worker hasn’t been vaccinated for it.
Why are nail tips made pointed?
The ends of the nails and pins are made sharp in order to minimize the area which in turn increases the pressure.So when you hit the nail on its head , even a small force converts into a large pressure due to the small area of the tail and the nail is able to insert in the wall.
Why do iron nails have pointed tips?
Iron nails have pointed ends to decrease contact area and to increase pressure so that it can penetrate easily. to exert more pressure to penetrate by applying less at the top.
Why is the tip of my nail pointed?
Solution. The tip of a nail is sharp and pointed because the area under the pointed end of the sharp nail is very small. Therefore, the pressure exerted by a sharp nail is more on the wall and it can pierce easily on the wall with less amount of work done.