What is the mechanical energy of the cart on the right at position A. The
cart is not in motion. (height=15 m, mass = 12 kg, gravity = 10 m/s2)?

1800 J

Step-by-step explanation:

At point A when the cart is not in motion, it only has potential energy.

We know that potential energy is given by mgh where m is the mass of the cart, g is acceleration due to gravity and h is the height.

Substituting 12 kg for m, 10 m/s2 for g and 15 m for h then

PE= 12*10*15=1800 J