Friction on an incline and velocity

In summary: At the horizontal surface, There is no friction. So there is no change in kinetic energy Which mean there is no change in the total energyBut on the incline, I have an external force acting on it which is friction of course.and work is W = f*d cos theta.What does work do? if the work is positive then it adds energy to the object. If it is negative then it takes away energy.Now think of the initial position and the final position, What kind of energy does the object have at these moments?Hint: at the end of the movement, The velocity is zero and it is not at the ground level so there is height (What form of
  • #1
df102015
27
1

Homework Statement


A block is sliding with an initial velocity of 7.3 m/s along a frictionless horizontal surface when it then goes up an incline of 51.5 degrees that does have friction. If the kinetic friction coefficient is 0.1 then how far along the incline (hypotenuse) will the object travel before it stops?
7-p-044.gif


Θ = 51.5°
µ(k) = 0.1
v(initial) = 7.3 m/s
v(final) = 0 ...because the question asks at what point will it stop, meaning there is no more speed.
g = 9.81
d = ?
m = ?
a = ? ...i do not know if i even need acceleration
F = ?
W = ?

Homework Equations


KE = W = 1/2mv(final) - 1/2mv(initial)
F = mg
W = Fd
Force up ramp... F = mg sinΘ
Normal Force against ramp... Fnormal = mg cosΘ
Force of friction between block and ramp... F(f) = µ Fnormal

The Attempt at a Solution


Honestly i have no clue where to even begin, i am so lost on this problem :(
Also, my equations could be wrong.
 
Physics news on Phys.org
  • #2
Okay, Let's think about it together alright?

At the horizontal surface, There is no friction. So there is no change in kinetic energy Which mean there is no change in the total energy
But on the incline, I have an external force acting on it which is friction of course.
and work is W = f*d cos theta.
What does work do? if the work is positive then it adds energy to the object. If it is negative then it takes away energy.

Now think of the initial position and the final position, What kind of energy does the object have at these moments?

Hint: at the end of the movement, The velocity is zero and it is not at the ground level so there is height (What form of energy is that?)

Put it in an equation describing what happens to the total energy and volaaa you have solved it!
 
  • Like
Likes df102015
  • #3
Biker said:
Okay, Let's think about it together alright?

At the horizontal surface, There is no friction. So there is no change in kinetic energy Which mean there is no change in the total energy
But on the incline, I have an external force acting on it which is friction of course.
and work is W = f*d cos theta.
What does work do? if the work is positive then it adds energy to the object. If it is negative then it takes away energy.

Now think of the initial position and the final position, What kind of energy does the object have at these moments?

Hint: at the end of the movement, The velocity is zero and it is not at the ground level so there is height (What form of energy is that?)

Put it in an equation describing what happens to the total energy and volaaa you have solved it!

Okay i think i get what you're saying, so it starts with kinetic energy and ends with gravitational potential energy. But what equations, i don't know which ones i could use...
 
  • #4
Well I know that
W = E2- E1
Substitute these values with what you have.
For example E1 should be kinetic energy.
 
  • Like
Likes df102015

1. How does the angle of an incline affect the amount of friction?

The steeper the incline, the greater the amount of friction. This is because as the angle increases, the force of gravity pulling the object down the incline also increases, creating a larger normal force between the object and the surface. This normal force creates a larger frictional force.

2. Does the mass of the object affect the friction on an incline?

Yes, the mass of the object does affect the amount of friction on an incline. This is because the weight of the object, which is directly related to its mass, influences the normal force and therefore the frictional force. A heavier object will have a greater normal force and a larger frictional force compared to a lighter object on the same incline.

3. How does the coefficient of friction affect the velocity of an object on an incline?

The coefficient of friction, which is a measure of the roughness between two surfaces, affects the velocity of an object on an incline by determining the amount of frictional force between the object and the surface. A higher coefficient of friction will result in a slower velocity, as more force is needed to counteract the friction and maintain the object's motion.

4. Can an object accelerate while moving up an incline?

Yes, an object can accelerate while moving up an incline. This is because the force of gravity pulling the object down the incline is counteracted by the normal force and frictional force, allowing the object to move upward. The amount of acceleration will depend on the incline angle, mass of the object, and coefficient of friction.

5. How can the velocity of an object on an incline be calculated?

The velocity of an object on an incline can be calculated using the formula v = √(2as), where v is the velocity, a is the acceleration, and s is the distance traveled. The acceleration on an incline can be determined using the formula a = gsinθ, where g is the acceleration due to gravity and θ is the angle of the incline. The distance traveled can be found using the formula s = ut + ½at², where u is the initial velocity and t is the time.

Similar threads

  • Introductory Physics Homework Help
Replies
2
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
1K
  • Introductory Physics Homework Help
Replies
5
Views
1K
  • Introductory Physics Homework Help
Replies
18
Views
2K
  • Introductory Physics Homework Help
Replies
7
Views
3K
  • Introductory Physics Homework Help
Replies
2
Views
821
  • Introductory Physics Homework Help
Replies
2
Views
1K
  • Introductory Physics Homework Help
2
Replies
56
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
11
Views
1K
Back
Top