Block pulled on horizontal surface -w/friction-

In summary, the problem presents a box being pulled by a force of 15 N at an angle of 20° above the horizontal on a surface with a coefficient of friction of 0.15. After traveling a distance of 10 m, the final velocity and kinetic energy of the box need to be determined. Using the equations of motion, the normal force and frictional force are found to be 74.87 N and 11.23 N, respectively. The final velocity is calculated using the equation v_{end} = at, and the kinetic energy can be found using the equation K.E. = 0.5mv^2. Additionally, the work done on the box can be expressed as F*d, where F
  • #1
bdragons
2
0

Homework Statement


A box weighing 80N is pulled along a horizontal surface by a force of 15 N which is directed at 20° above the horizontal. If the box started from rest and the coefficient of friction is 0.15, find the kinetic energy and velocity of the box after it traveled a distance of 10 m.

Homework Equations


Normal force= W-Tsinθ
Frictional force=μk x Normal force

The Attempt at a Solution


First I looked for normal force which turns out as 74.87 then frictional force which is 11.23 after that, I don't get how to find velocity. I just need final velocity at this point to get average velocity=velocity then having V, I could solve for K.E.
 
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  • #2
Force accelerates the box's speed.
It has a speed of 0m/s in the beginning.
[itex]x = x_0 + v_0t + 0.5at^2[/itex]
[itex]x = 0.5at^2[/itex]
On the other hand
[itex]v_{end} = v_0 + at[/itex]
[itex]v_{end} = at[/itex]
Should be all the info you need. Think about it.
 
  • #3
would just like to clear the following things:
-what does x,x0,v0 stand for? (guessing that 0 there means zero)
-does a stand for acceleration while t is time?
 
  • #4
They're the basic equations of motion.
x = total distance
x_0 = distance from origin(usually 0 unless origin is set somewhere else than on the system you're investigating)
v_0 = speed the system has when you begin investigating it
a = acceleration
t = time
 
  • #5
If you know the net force F moves the block, acting in the direction of motion, then the work done on the block moving it distance d is given by F*d. Where does that work end up (how is it expressed in the system)?
 

1. What is the definition of a block pulled on a horizontal surface with friction?

A block pulled on a horizontal surface with friction refers to a scenario where an object, such as a block, is placed on a flat surface and is being pulled or dragged across that surface with some amount of resistance or friction present.

2. How does friction affect the motion of the block in this scenario?

Friction acts as a force that opposes the motion of the block, making it more difficult to move the block across the surface. This force is dependent on the type of surface and the weight of the block.

3. What factors contribute to the amount of friction present in this scenario?

The amount of friction present in this scenario is influenced by several factors, including the type of surface the block is being pulled on, the weight of the block, the force applied to pull the block, and the roughness of the surfaces in contact.

4. How does the angle of the force applied to pull the block affect the amount of friction?

The angle of the force applied to pull the block can impact the amount of friction present. If the force is applied at a greater angle, there will be a larger component of the force acting parallel to the surface, resulting in more friction.

5. How can the coefficient of friction be calculated in this scenario?

The coefficient of friction can be calculated by dividing the magnitude of the frictional force by the normal force acting on the block. This can be determined through experiments or by using known values for the materials in contact.

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