Calculating the Force Needed to Slide a 400 N Box Up a Ramp

[brad_i2001]

Homework Statement

A large package weighing 517 N is accelerated across a gym floor at 3 m/sec^2 because it is being pushed at a force of 285 N at 50 degrees to the floor. What is the normal force of the package? What is the coefficient of sliding friction between the package and the floor? Approximately what percentage of the 285 N force is being wasted due to the excessive angle produced by the pusher?

Homework Equations

F=MA
HORIZONTALLY
FORCE APPLIED, X= (285)(cos 50)= 183.194

VERTICALLY
FORCE OF Y=0 (not rising off the ground)
FORCE APPLIED, Y= (285)(sin 50)= 218.323

The Attempt at a Solution

I have filled in as much as I know, please help!
Thanks

Homework Statement

In order to slide a 400 N box up a 25 degree ramp at a constant speed, a force of 250 N parallel to to the surface is required

Homework Equations

The Attempt at a Solution

 

[bob1182006]

for the first problem:

what is the normal force of the box?

how would you setup Newton's Second Law in order to find the coefficient of friction?

and to find the % being wasted take (Force Applied - Total Force being Exerted)/Total Force being Exerted * 100%

And what is the question for your second problem?

 

[brad_i2001]

Wouldn't you use F=MA to find normal force?