Answer:
v = 12.12 m/s
Explanation:
Given that,
The mass of the cart, m = 75 kg
The roller coaster begins 15 m above the ground.
We need to find the velocity of the cart halfway to the ground. Let the velocity be v. Using the conservation of energy at this position, h = 15/2 = 7.5 m

So, the velocity of the cart is 12.12 m/s.
Answer:
there is friction between the two things
Explanation:
The subscript after the element indicates the number of atoms of that element in the molecule. So, in H20, the subscript after the H, which stands for hydrogen, is 2. This means that there are 2 hydrogen atoms in a water molecule.
Hope this helps! :)
Hello Again! I think the Answer might be 220 m! ( 1/2) ( 21 m/s + 0 m/s) (21 s) = 220 m
..............no.......................