Okay, so I totally don't understand what to do with these three. Could you please show how to solve? I don't need to see the solution, just what steps I need to take for each (every smallest detail please).

Question

1. A box weighing 150 N is at rest on a horizontal floor. The coefficient of static friction is 0.4. What is the smallest force F exerted eastward and upward at an angle of 350 with the horizontal that can start the box in motion?

2. A 450 kg fully loaded elevator is moving downward. The tension in the cable is 3500 N. What is the elevator's acceleration?

3. A 55 kg box slides across the floor by a force of 25N [there was a picture to go along with this, it showed a dotted line going horizontally from the top of the box and making a 45 degree angle].
a.) How large a friction force impedes the motion of the box?
b.) How large is the normal force?

Answer 1

I wish I could help but I hate physics and it would take me forever to find your answer and forever to show you the steps

Answer 2

1. A box weighing 150 N is at rest on a horizontal floor. The coefficient of static friction is 0.4. What is the smallest force F exerted eastward and upward at an angle of 350 with the horizontal that can start the box in motion?
****The force is pulling horizontally, and upward (reducing weight).
normal force=mg - Fcosine350
horizonal force=Fsine350=forcenormal*mu

F sin350=(mg-Fcos350)mu
solve for F
2. A 450 kg fully loaded elevator is moving downward. The tension in the cable is 3500 N. What is the elevator's acceleration?
****Tension=mg-ma
solve for a

3. A 55 kg box slides across the floor by a force of 25N [there was a picture to go along with this, it showed a dotted line going horizontally from the top of the box and making a 45 degree angle].
a.) How large a friction force impedes the motion of the box?
b.) How large is the normal force?
***Work this the same as number one.