Question

Which of the following is not a contact force?
a Friction
b. Gravitation
C. Tension
d. Normal reaction​

Answer 1

Answer:

b. Gravitation

Explanation:

Friction is clearly the force produced when two surfaces rub against each other. This force is the reason why heat is produced whenever two surfaces come in contact.

Tension is also the force exerted when a spring or string is stretched and it is also potential to objects attached to it.

Normal reaction is the push exerted by a surface on an object pressing on it - always perpendicular to the surface. E.g is a cup on a table. The cup is being pulled towards the ground by gravity but the table is supporting it back with normal reaction, the same amount of force the cup is acting on the table.

Gravitation is the pulling force of the Earth on any object no matter where they are.