Thanks for the questions! 1. In this scenario, we're not told whether the blocks are accelerating or not. For each block, the net horizontal force is equal to its own mass times its acceleration (Newton's 2nd law, Fnet=ma). If the blocks are not accelerating then F1=F2, Fn(B on A)=F1, and Fn(A on B)=F2. And it's always true that Fn(B on A)=Fn(A on B) because they're a pair of equal and opposite forces. 2. If F1 or F2 was greater than the other then the blocks will accelerate together at the same rate, and the relationship between the horizontal forces will depend on masses of block A and block B. There will still be a normal force between the blocks when accelerating, and they will always be equal to each other. However, if we removed F1 and F2 then there is nothing pushing the blocks into each other and there would not be a normal force between the blocks. There would be a normal force if only F1 or F2 was still acting on the blocks, causing one block to accelerate the other block. 3. In order to figure out how the normal force between two bodies is related to the other forces, you need to write out Newton's 2nd law (Fnet=ma) in the horizontal direction. The relationship between the forces will depend on the acceleration and the masses. 4. Yes a normal force is always normal (perpendicular) to the contact surface between the two objects. So the normal force by a book on a table is equal in magnitude and opposite in direction to the normal force by the table on the book. This is true for any two bodies that are in contact. I hope this helps!

@@physicslab42 yes, it helped. thanks.

That’s awesome to hear thanks, I’m glad it helped!

Good question! If you don't know any of the angles in the right triangle (and you can't find them from other angles that are given) then you wouldn't be able to find the x and y components. The question would have to give you an angle and tell you which angle it is.

I’m glad to hear the video helped, thank you for your comment!

Good question! You can actually combine scientific notation and prefixes. So if something is 1 x 10^24 kg then it would be equal to 1 x 10^27 g (the exponent would increase by 3 if you convert from kg to g).

Thanks I’m glad they help! Working on Newton’s 3rd law next.

Thanks!

Yeah that's a common point of confusion. The acceleration of g (9.8 m/s²) is caused by gravity, which always acts downwards no matter what's happening, gravity and the acceleration never act upwards. So even if an object is moving up (it's velocity is up) the acceleration is still down. That has the effect of slowing down the speed of an object moving up, and speeding up an object if it's moving down. Does that help or still confused?

More videos coming soon!

I have a few videos on vectors if you want to check them out! Vectors and Components: kzbin.info/www/bejne/b2elf3mJfq6Sj68 Displacement Vectors: kzbin.info/www/bejne/jZK2qqeoarqno6csi=SS2uIUUm3EUIZj7S Velocity Vectors: kzbin.info/www/bejne/rYO9ZWuCntWXbcUsi=RLixmNJufR_ubPrU 2D Motion and Vectors - Practice Problems: kzbin.info/www/bejne/inybc2yifaimbZIsi=EuQ0PgdUsHSFfsqv

Yup if you are writing a number in scientific notation you would move the decimal until there is one digit to the left of it. The number of places you moved the decimal is the exponent above the 10 (the exponent is positive if you moved the decimal left and negative if you moved it right).

Awesome I’m glad they’re helping!

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Thank you so much! I have more videos and content for teachers in the Physics 1 course if they're interested: physicslab.app/p/physics-1