Contact force between two boxes

Question

Assignment:

Question 1. Three boxes rest side-by-side on a smooth, horizontal floor. Their masses are 5.0 kg, 3.0 kg, and 2.0 kg, with the 3.0-kg mass in the center. A force of 50 N pushes on the 5.0-kg mass, which pushes against the other two masses. What is the contact force between the 3.0-kg mass and the 2.0-kg mass?

• 0 N
• 10 N
• 25 N
• 40 N

Question 2. Three boxes rest side-by-side on a smooth, horizontal floor. Their masses are 5.0 kg, 3.0 kg, and 2.0 kg, with the 3.0-kg mass in the center. A force of 50 N pushes on the 2.0-kg mass, which pushes against the other two masses. What is the contact force between the 3.0-kg mass and the 2.0-kg mass?

• 0 N
• 10 N
• 25 N
• 40 N