Answer:
7. Net constant force down the ramp
Step-by-step explanation:
After the car is released and starts moving up the ramp, the only force that is applied on the car is weight because of the gravity, we were told that the friction force is neglected. the force because of the weight is given by:
![F=m*g*sin(\theta)](https://img.qammunity.org/2020/formulas/physics/high-school/kdy0hgrt9jsvx9zt9ishk29duccjzb3bli.png)
where θ is the angle of the ramp.
as you can see those values won't change, so the force remains constant down the ramp.