Calculate the magnitude of the normal force on a 15.0-kg block in the following circumstances: (a) T

Calculate the magnitude of the normal force on a 15.0-kg block in the following circumstances: (a) The block is resting on a level surface. (b) The block is resting on a surface tilted up at a 30.0° angle with respect to the horizontal. (c) The block is resting on the floor of an elevator that is accelerating upwards at 3.00 m/s^2. (d) The block is on a level surface and a force of 125 N is exerted on it at an angle of 30.0° above the horizontal .

[AldasLevisauskas]

This video is wrong however, the equation is supposed to subtract 125Sin30 from (15)(9.8). therefor the answer should be 84.5

[Diazdayplants]

I'm so confused about the rationale in C. because if The sum of all Y forces is Fn - mg, but it is also equal to ma, how can Fn also equal ma, and Fn equal mg as well. I think I might be confusing myself but im just trying to make a logic behind it.

[esterlopez]

This video helped me out so much and you explained everything very well. Thank you so much.

[palvimall]

In the back of the textbook, it is the same answers for a, b, c but for d) it shows 84.5N