# Normal force?

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#### Drrrrrr. Celty

##### Osteo Dullahan
10+ Year Member

So I was looking at Ek Physic and they said for inclined planes that Mgsin = the Normal force, then also said Mgcos = Normal force, and then later said that Mgsin = the net total force.

Can someone explain what they mean?

##### MD
Moderator Emeritus
10+ Year Member
mgcos(theta) is the normal force on an object atop an inclined plane.

mgsin(theta) is the component force of gravity on the object parallel to the plane. In the sense that there is no upward (up the plane) force on an object, and that the component force of gravity perpendicular to the inclined plane (equal to the normal force, mgcos(theta)), the mgsin component of gravity can be considered the net force on the object.

#### Drrrrrr. Celty

##### Osteo Dullahan
10+ Year Member
mgcos(theta) is the normal force on an object atop an inclined plane.

mgsin(theta) is the component force of gravity on the object parallel to the plane. In the sense that there is no upward (up the plane) force on an object, and that the component force of gravity perpendicular to the inclined plane (equal to the normal force, mgcos(theta)), the mgsin component of gravity can be considered the net force on the object.

Alright that makes sense. I remember Mgsin being the net force/ gravity. But I didn't quite understand that comment in Ek Physics, must have been a typo.

#### Temperature101

##### Membership Revoked
Removed
Alright that makes sense. I remember Mgsin being the net force/ gravity. But I didn't quite understand that comment in Ek Physics, must have been a typo.

EK has many of them....

#### YouNeverKnow22

##### Full Member
7+ Year Member
here's a figure I always draw before any inclined problem (forgive my lack of artistic capabilities).  