Can't find my other post and I know the person who helped me wanted to know if it was right or no. And it wasn't.

So Ff=UsFN
Ff=49N

-Ff=ma
a=-6.86 on the penguin

Fnet=ma
Fa-Ff=ma
Fa-49=6.12*6.86
Fa=90.98N

There it is.

Thank you.

It seems like you're saying that you had a previous post where someone helped you with some calculations, and now you can't find that post. Now, you want to confirm if your calculations are correct. I can help you understand if your calculations are accurate.

From your post, you have provided the following equations:

1. Ff = UsFN
2. Ff = 49N

It seems like these equations are related to the force of friction (Ff) and the normal force (FN) with the coefficient of static friction (Us). However, without further context or information, it is not clear what these values represent.

Next, you mentioned the equation:

3. -Ff = ma

This equation relates the force of friction (Ff) to the mass (m) and acceleration (a) of an object. You stated that the acceleration (a) is -6.86 m/s^2 on the penguin. It's worth noting that a negative acceleration indicates opposite direction to the positive coordinate system.

Finally, you provided the equation:

4. Fnet = ma
Fa - Ff = ma

This equation is related to the net force (Fnet) acting on an object, which equals the product of its mass (m) and acceleration (a). By rearranging the equation, you solved for the force applied (Fa) by getting:

Fa = 90.98N

Based on these calculations, it seems like you have confirmed that the force applied (Fa) is approximately 90.98N. However, without additional information or context, it is difficult to determine if these calculations are correct or if they pertain to a specific problem.

If you are trying to find a previous post, I suggest checking your browsing history, searching your email or messaging conversations, or referring to saved files or documents where you may have posted the question and received a response.