To determine the net acceleration of the stroller, we need to calculate the net force acting on it and then use Newton's second law $F = ma$.

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Step 1: Forces acting on the stroller

Horizontal component of applied force:

The force $F_{\text{applied}}$ of 90 N is applied at an angle of $18^\circ$ below the horizontal. The horizontal component of the force is: $F_{\text{horizontal}} = F_{\text{applied}} \cos \theta$ Substitute the values: $F_{\text{horizontal}} = 90 \cos(18^\circ)$

Vertical component of applied force:

The vertical component of the applied force is: $F_{\text{vertical}} = F_{\text{applied}} \sin \theta$ Substitute the values: $F_{\text{vertical}} = 90 \sin(18^\circ)$

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Step 2: Normal force calculation

The normal force ($F_{\text{normal}}$) is affected by the combined weight of the stroller and the daughter, as well as the vertical component of the applied force: $F_{\text{normal}} = (m_{\text{stroller}} g) - F_{\text{vertical}}$ Where:

• $m_{\text{stroller}} = 19.2 \, \text{kg}$
• $g = 9.8 \, \text{m/s}^2$

Substitute: $F_{\text{normal}} = (19.2 \cdot 9.8) - F_{\text{vertical}}$

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Step 3: Frictional force calculation

The frictional force ($F_{\text{friction}}$) opposes motion and is given by: $F_{\text{friction}} = \mu F_{\text{normal}}$ Where $\mu = 0.235$.

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Step 4: Net force calculation

The net horizontal force ($F_{\text{net}}$) is: $F_{\text{net}} = F_{\text{horizontal}} - F_{\text{friction}}$

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Step 5: Net acceleration calculation

Using Newton's second law ($F = ma$): $a = \frac{F_{\text{net}}}{m_{\text{stroller}}}$

Now let's calculate the values step-by-step.

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Step-by-step calculation:

1. Calculate horizontal and vertical components of the applied force: $F_{\text{horizontal}} = 90 \cos(18^\circ) \approx 85.47 \, \text{N}$ $F_{\text{vertical}} = 90 \sin(18^\circ) \approx 27.81 \, \text{N}$

2. Calculate the normal force: $F_{\text{normal}} = (19.2 \cdot 9.8) - 27.81 \approx 161.76 \, \text{N}$

3. Calculate the frictional force: $F_{\text{friction}} = 0.235 \cdot 161.76 \approx 38.44 \, \text{N}$

4. Calculate the net horizontal force: $F_{\text{net}} = 85.47 - 38.44 \approx 47.03 \, \text{N}$

5. Calculate the net acceleration: $a = \frac{F_{\text{net}}}{m_{\text{stroller}}} = \frac{47.03}{19.2} \approx 2.45 \, \text{m/s}^2$

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Final Answer:

The net acceleration of the stroller is approximately: $\boxed{2.45 \, \text{m/s}^2}$

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Would you like a detailed breakdown of any step?

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Related Questions:

1. How does the angle of applied force affect acceleration?
2. What role does the coefficient of friction play in motion?
3. How would acceleration change if the force applied were horizontal?
4. How is the normal force adjusted by the vertical component of an applied force?
5. What happens if the surface were inclined instead of flat?

Tip: Always decompose forces into horizontal and vertical components for problems involving angles.