Car is moving on the glassy slope with constant speed
Now we know that

so acceleration is rate of change in velocity
as we know that velocity is constant here so acceleration is zero
so here

now as we know by Newton's II law

since a = 0

so net force will be ZERO on it during this motion
Explanation:
Below is an attachment containing the solution.
3. Sand has a low specific heat compared to air
theanswer is b.heart disease