Let's break down the problem step by step to solve for the normal force, acceleration, and net force.

1. Normal Force:

• The normal force ($F_N$) is the force exerted by a surface to support the weight of an object. It typically acts perpendicular to the surface.
• The weight of the object is given by: $W = mg$ where $m = 8.5 \, \text{kg}$ is the mass of the object, and $g = 9.8 \, \text{m/s}^2$ is the acceleration due to gravity. $W = 8.5 \times 9.8 = 83.3 \, \text{N}$ If there is no vertical acceleration, the normal force equals the weight of the object: $F_N = 83.3 \, \text{N}$

2. Net Force:

• The net force is the total force acting on the object, considering all applied forces, including friction.
• The applied force is 60 N, and the frictional force is 11 N (which acts in the opposite direction). $F_{\text{net}} = 60 \, \text{N} - 11 \, \text{N} = 49 \, \text{N}$

3. Acceleration:

• Using Newton's second law, $F_{\text{net}} = ma$, we can solve for acceleration: $a = \frac{F_{\text{net}}}{m}$ $a = \frac{49}{8.5} \approx 5.76 \, \text{m/s}^2$

Answers:

• Normal Force: 83.3 N
• Net Force: 49 N
• Acceleration: 5.76 m/s²

Let me know if you need further clarification or want more details. Here are some related questions:

1. How do you calculate frictional force in more complex problems?
2. What happens to acceleration if friction increases?
3. Can normal force ever be greater than weight? If so, in what cases?
4. How would you solve this problem if the surface were inclined?
5. What are the effects of changing the mass on acceleration and net force?

Tip: Always keep track of the direction of forces; friction always opposes motion!