Normal Force of an object being pushed

AI Thread Summary
When pushing an 8.00 kg suitcase at an angle of 35.4 degrees below the horizontal, the normal force exerted by the ground must counteract both the gravitational force and the vertical component of the applied force. The gravitational force is calculated as 80 N (8 kg x 10 m/s²), while the horizontal acceleration of 1.26 m/s² indicates additional forces at play. Friction acts parallel to the surface, and its magnitude is directly related to the normal force. The normal force acts perpendicular to the surface to balance the vertical forces, ensuring the suitcase does not move into the ground. Understanding these dynamics is crucial for accurately calculating the normal force in this scenario.
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You push a 8.00 kg suitcase across a smooth horizontal floor applying a force directed 35.4 degrees below the horizontal. Someone measures the acceleration of the suitcase to be 1.26 m/s2.

Assuming g = 10.0 m/s2, what is the normal force the ground exerts on the suitcase?


So is normal friction opposite to gravity always or opposite of total direction?

Well force of gravity is F=8(10)
Force horizontal is F=1.26(8)

Then what? thanks
 
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So is normal friction opposite to gravity always or opposite of total direction?
Don't understand the question.

Friction is along a surface, not normal to it.
The magnitude of the friction is proportional to the magnitude of the normal force to the surface - the harder you press into the surface the greater the resistance to moving along the surface.

In this case, part of the applied force is along the surface and part is into the surface.
Since the object does not move into the surface, there must be a force from the surface acting against the force into the surface to cancel it out. This is usually called "the normal force" - since it acts 90deg to the surface.

Your free body diagram should show the applied force at an angle, weight pointing down, and the normal force pointing up.
The sum of these forces should be a net unbalanced force pointing horizontally.

Hopefully something in there solves your confusion.
 
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