A child pulls a wagon by the handle along a flat sidewalk.

In summary, a child exerts a force of 80.0 N at a 30.0° angle above the horizontal to pull a trolley 12 m along a flat sidewalk. The force of friction on the trolley is 34 N. For part (a), the mechanical work done by the child on the trolley is calculated to be 148J. For part (b), the net work done on the trolley is calculated by considering the work done by the child and the work done by other forces on the trolley.
  • #1
SilentWind12
1
0

Homework Statement


A child pulls a trolley by the handle along a flat sidewalk. She exerts a force of 80.0 N at an angle of 30.0° above the horizontal while she moves the wagon 12 m forward. The force of friction on the trolley is 34 N.

Homework Equations


(a) Calculate the mechanical work done by the child on the trolley.
(b) Calculate the total work done on the trolley

The Attempt at a Solution


W=F(cos)
80 cos(30)[/B]
W=Fcosdeltad
W=80 N(cos30)(12)
=148J

b)Idk how to do it.
 
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  • #2
SilentWind12 said:
W=80 N(cos30)(12)
=148J
Try that last step again, taking note that it is 30 DEGREES.
For b), what else is doing work on the trolley? How much work? Positive or negative?
 
  • #3
SilentWind12 said:
(b) Calculate the total work done on the trolley
This could be worded: Calculate the net work done on the trolley.
 

Related to A child pulls a wagon by the handle along a flat sidewalk.

1. What is the force required to pull a wagon along a flat sidewalk?

The force required to pull a wagon along a flat sidewalk depends on several factors such as the weight of the wagon, the friction between the wheels and the sidewalk, and the strength of the child pulling the wagon. It is generally easier to pull a lighter wagon with smoother wheels.

2. How does the weight of the wagon affect the force required to pull it?

The heavier the wagon, the more force is required to pull it along a flat sidewalk. This is because the weight of the wagon increases the downward force of gravity, which creates more friction between the wheels and the sidewalk.

3. Is it easier to pull a wagon with larger or smaller wheels?

Generally, larger wheels make it easier to pull a wagon along a flat sidewalk. This is because larger wheels have a larger surface area, which reduces the amount of friction between the wheels and the sidewalk. Smaller wheels may have more difficulty rolling over bumps or cracks in the sidewalk, making it harder to pull the wagon.

4. What is the difference between pulling a wagon and pushing a wagon?

When pulling a wagon, the child exerts a force in the direction that they want the wagon to move. This force is applied through the handle of the wagon and is typically greater than the weight of the wagon. When pushing a wagon, the child exerts a force in the opposite direction of the desired movement. This force must be greater than the weight of the wagon in order to overcome friction and move the wagon forward.

5. How can the force required to pull a wagon be reduced?

The force required to pull a wagon can be reduced by making adjustments to the wagon, such as using smoother wheels or reducing the weight of the wagon. Additionally, the child can reduce the force required by walking at a steady pace and avoiding sudden stops or changes in direction.

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