Two children are pulling and pushing a 30.0 kg sled. The child pulling the sled is exerting a force of 12.0 N at a 45° angle. The child pushing the sled is exerting a horizontal force of 8.00 N. There is a force of friction of 5.00 N.

1. What is the weight of the sled? ______ N
2. What is the normal force exerted on the sled? (Round the answer to the nearest whole number) ______ N
3. What is the acceleration of the sled? (Round the answer to the nearest hundredth) ______ m/s²



Answer :

Let's walk through the problem step-by-step to find the required forces and the acceleration of the sled.

### 1. Calculate the weight of the sled

The weight of the sled can be determined using the formula:
[tex]\[ \text{Weight} = \text{mass} \times \text{gravity} \][/tex]

Given:
- Mass of the sled, [tex]\( \text{mass\_sled} = 30.0 \, \text{kg} \)[/tex]
- Acceleration due to gravity, [tex]\( g = 9.8 \, \text{m/s}^2 \)[/tex]

Therefore:
[tex]\[ \text{Weight} = 30.0 \, \text{kg} \times 9.8 \, \text{m/s}^2 = 294.0 \, \text{N} \][/tex]

So, the weight of the sled is:
[tex]\[ \boxed{294.0 \, \text{N}} \][/tex]

### 2. Calculate the normal force exerted on the sled

To determine the normal force, we need to account for the vertical component of the pulling force, which affects the normal force since it lifts the sled partially.

First, calculate the vertical component of the pulling force:
[tex]\[ \text{Pulling Force (Vertical)} = 12.0 \, \text{N} \times \sin(45^\circ) \][/tex]

Since [tex]\( \sin(45^\circ) = \frac{\sqrt{2}}{2} \approx 0.707 \)[/tex]:
[tex]\[ \text{Pulling Force (Vertical)} = 12.0 \, \text{N} \times 0.707 = 8.484 \, \text{N} \][/tex]

The normal force is the weight of the sled minus the vertical component of the pulling force:
[tex]\[ \text{Normal Force} = \text{Weight} - \text{Pulling Force (Vertical)} \][/tex]

Therefore:
[tex]\[ \text{Normal Force} = 294.0 \, \text{N} - 8.484 \, \text{N} = 285.516 \, \text{N} \][/tex]

Rounding to the nearest whole number:
[tex]\[ \boxed{286 \, \text{N}} \][/tex]

### 3. Calculate the acceleration of the sled

To determine the acceleration, we need the net horizontal force and then use Newton's second law.

First, calculate the horizontal component of the pulling force:
[tex]\[ \text{Pulling Force (Horizontal)} = 12.0 \, \text{N} \times \cos(45^\circ) \][/tex]

Since [tex]\( \cos(45^\circ) = \frac{\sqrt{2}}{2} \approx 0.707 \)[/tex]:
[tex]\[ \text{Pulling Force (Horizontal)} = 12.0 \, \text{N} \times 0.707 = 8.484 \, \text{N} \][/tex]

Next, compute the net horizontal force by summing the horizontal components of all forces and subtracting the friction force:
[tex]\[ \text{Net Horizontal Force} = \text{Pulling Force (Horizontal)} + \text{Pushing Force} - \text{Friction Force} \][/tex]

Given:
- Pushing Force = [tex]\( 8.00 \, \text{N} \)[/tex]
- Friction Force = [tex]\( 5.00 \, \text{N} \)[/tex]

[tex]\[ \text{Net Horizontal Force} = 8.484 \, \text{N} + 8.00 \, \text{N} - 5.00 \, \text{N} = 11.484 \, \text{N} \][/tex]

Finally, use Newton's second law to find the acceleration:
[tex]\[ \text{Acceleration} = \frac{\text{Net Horizontal Force}}{\text{Mass}} \][/tex]

Therefore:
[tex]\[ \text{Acceleration} = \frac{11.484 \, \text{N}}{30.0 \, \text{kg}} = 0.3828 \, \text{m/s}^2 \][/tex]

Rounding to the nearest hundredth:
[tex]\[ \boxed{0.38 \, \text{m/s}^2} \][/tex]