Calculate the forces of a mover pushing a crate

[raman911]

Homework Statement

A mover pushes a 85kg crate along the floor at a constant speed through a displacement of 3,1m[E]. The coefficient of kinetic friction between the floor and crate is 0.22.
A) Calculate Fn and Fapp.

The Attempt at a Solution

Fg=mg
=85kg*9.8N/kg
Fg=833N
So Fn=Fg
but how can i find Fapp

 

[denverdoc]

You may want to review friction;

Fn=weight since it is vertical. But frictional force is a fraction of this. Hint:There is a constant that you are not using.

 

[chouZ]

make a body diagram and it will be more clear. Net force of the forces in the direction of the displacement equal the product of mass and acceleration. Solve for Fapp..

 

[chouZ]

Net force= forces applied on the axis of the displacement

 

[raman911]

Net force= forces applied on the axis of the displacement

i don't know net force

 

[arildno]

i don't know net force

Sure you do.
You know the crate moves with constant velocity.

What does that mean, in terms of net force acting upon the crate?

 

[raman911]

Sure you do.
You know the crate moves with constant velocity.

What does that mean, in terms of net force acting upon the crate?

i don't understand that

 

[arildno]

If an object moves with constant velocity, what is its acceleration?
And how is acceleration tied together with forces?

 

[raman911]

If an object moves with constant velocity, what is its acceleration?
And how is acceleration tied together with forces?

but i need time to find acceleration

 

[arildno]

but i need time to find acceleration

Eeeh, why?

 

[harmonicmotion]

i need help with AP Physics free response questions

 

[harmonicmotion]

its the 2002 ap physics c queston

 

[arildno]

i need help with AP Physics free response questions

Then make your own thread!

 

[harmonicmotion]

could someone reply if they are willing to help

 

[raman911]

$$Given$$

$$m=0.2kg$$
$$\Delta {h}_{2}=0m$$
$${v}_{2}=3.96m/s$$

$$Required$$

$${E}_{g} and {E}_{k}$$

$$Solution$$

$${E}_{g}={m}g\Delta h$$
$$={0.2kg}*9.8N/kg*0m$$
$${E}_{g}=0J$$$${E}_{k}=(1/2)m{v}_{2}^2$$
$$=(1/2)0.2Kg(3.96m/s)^2$$
$${E}_{k}=1.56J$$