# What is difference between normal force and reaction force? [duplicate]

according to my book the perpendicular component of reaction force is called normal force when there is contact between two bodies. I can not understand that how for example when we jump we pushes the ground downward(action) and the ground pushes us upward(reaction) how this reaction is normal force? or for example if someone jumps to the shore from a boat, the boat moves in the opposite direction we push boat in backward direction and boat pushes us in forward direction(reaction) is this also normal force or friction force plz someone explain i dont understand.

Normal force in general is perpendicular component of force applied by surface on a body/System, In the context you are asking, When you jump, you use two component of forces to jump, One perpendicular to surface, Called "Normal force by surface" and and other is tangential to surface ,the friction, Which you use to move forward, as a vector sum of these force, you move up as well as forward, causing you to jump

In the situation mentioned, practically, you still use normal as well as friction to jump from boat to shore, In doing so, friction force on boat causes it to move in opposite direction of your jumping and normal force on boat causes the boat to move very little into the water, in other sense, water level rises around the boat..

• every reaction force which arises due to contact will always have 2components
– user379089
Oct 22, 2023 at 10:57
• Yes , Every reaction force can be represented as vector addition of Two components of that force "Perpendicular" to each other Oct 22, 2023 at 11:00
• okay. one more thing i would like to ask that when we throw a ball up in air or at any angle will the reaction force exrted by ball on me can also be represented as two components of that force ??
– user379089
Oct 22, 2023 at 11:03
• Yes, every Force In vector representation can be thought of a diagonal of rectangle and the two adjacent sides will be the two perpendicular components of that diagonal vector Oct 22, 2023 at 11:10
• thankyou very much now i understood
– user379089
Oct 22, 2023 at 11:11