Solution: Two blocks in contact are pushed up an inclined plane with a force 9mg, which is parallel to the plane. The force pushes on the lower block, which has mass 5m. The upper block has mass 4m. The plane i

Two blocks in contact are pushed up an inclined plane with a force 9mg, which is parallel to the plane. The force pushes on the lower block, which has mass 5m. The upper block has mass 4m. The plane is inclined at an angle θ **with respect to the vertical. **What is the magnitude of the force on the lower block exerted by the upper block?

1. 9mg

2. 5mg (1 − sin θ)

3. 5mg (1 − cos θ)

4. 4mg

5. 5mg cos θ

6. 5mg

7. 4mg cos θ

8. 4mg (1 − cos θ)

9. 4mg (1 − sin θ)