Force needed to push a trolley onto sidewalk

In summary, the minimum force required to push the trolley onto the curb can be found by considering the torque and normal forces acting on the wheels. The trolley will start to rotate about the front wheel when it has a positive torque about point b. Just before the wheel starts to roll onto the sidewalk, there will be no normal force acting on it. The force from the ground on the wheels will be normal to the contact plane between the trolley and the curb. Once the trolley starts to mount the curb, there will be normal forces acting on all of the wheels.
  • #1
Fibo112
149
3

Homework Statement


Find minimum Force needed to push the trolley onto the curb.

Homework Equations


Torque=r x F

The Attempt at a Solution


The front wheel will rotate about point b if the trolley is pushed onto the sidewalk. This should mean that as soon as the wheel has a positive torque about point b the trolley will move onto the sidewalk. I think that in the moment just before the wheel begins to roll onto the sidewalk there will be no normal force acting on it. What confuses me is how should I know which part of the weight is pushing onto the wheel and if the entire force F is acting on the wheel.
 

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  • #2
Fibo112 said:

Homework Statement


Find minimum Force needed to push the trolley onto the curb.

Homework Equations


Torque=r x F

The Attempt at a Solution


The front wheel will rotate about point b if the trolley is pushed onto the sidewalk. This should mean that as soon as the wheel has a positive torque about point b the trolley will move onto the sidewalk. I think that in the moment just before the wheel begins to roll onto the sidewalk there will be no normal force acting on it. What confuses me is how should I know which part of the weight is pushing onto the wheel and if the entire force F is acting on the wheel.
At the point where the wheel is about to rotate, what forces act on the trolley? What equations can you write?
 
  • #3
The forces acting are the gravitational force, the force the person imparts, the force that the curb imparts on the wheel and the normal force. Would it be correct to assume the in the moment before the wheel rotates the entire gravitational force is on the front wheels?
 
  • #4
Fibo112 said:
the normal force
The normal force where, exactly?
What direction is the force from the kerb?
 
  • #5
The force from the ground on the wheels. I'm not sure in which direction the force from the kerb is. I know it is usually normal to the surface but here is surface is a corner...
 
  • #6
Fibo112 said:
The force from the ground on the wheels
Which wheels? Consider the situation just after it starts to mount the kerb.
Fibo112 said:
I'm not sure in which direction the force from the kerb is. I know it is usually normal to the surface but here is surface is a corner...
The normal force is normal to the contact plane. What plane separates the two objects without cutting either?
 
  • #7
I guess one with a 45 degree angle...I would say that there is a normal force acting on all of the wheels..
 
  • #8
Fibo112 said:
I would say that there is a normal force acting on all of the wheels..
As I wrote, think about the situation just after it has started to mount the kerb. What are the normal forces on the wheels then?
 

FAQ: Force needed to push a trolley onto sidewalk

What factors affect the force needed to push a trolley onto a sidewalk?

The force needed to push a trolley onto a sidewalk depends on several factors, including the weight of the trolley, the angle of the sidewalk, the friction between the trolley and the ground, and the strength of the person pushing the trolley.

How does the weight of the trolley impact the force needed to push it onto a sidewalk?

The weight of the trolley directly affects the force needed to push it onto a sidewalk. The heavier the trolley, the more force will be required to overcome its inertia and move it onto the sidewalk.

Does the angle of the sidewalk affect the force needed to push a trolley onto it?

Yes, the angle of the sidewalk can have a significant impact on the force needed to push a trolley onto it. If the sidewalk is too steep, it may require more force to overcome the incline and push the trolley onto it.

How does friction affect the force needed to push a trolley onto a sidewalk?

Friction between the trolley and the ground can make it more difficult to push the trolley onto a sidewalk. If the ground is rough or the wheels of the trolley are not well-lubricated, it may require more force to overcome the friction and move the trolley onto the sidewalk.

Is the force needed to push a trolley onto a sidewalk the same for everyone?

No, the force needed to push a trolley onto a sidewalk can vary depending on the strength and physical ability of the person pushing it. Some individuals may require more force to push the trolley, while others may be able to push it with less force.

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