Answer:
350Joules
Explanation:
According to law of Conservation of energy, the amount of energy at the used up at the start is equal to that at the end.
The initial energy used up is gravitational potential energy
Final energy at the lowest point is kinetic energy.
If the energy is conserved then it means energy is not used up during the process hence;
Initial Potential energy = Final kinetic energy
If the gravitational potential energy is 350Joules then her final kinetic energy at the lowest point will also be 350Joules
Explanation:
Make a table, listing the x and y coordinates of each square's center of gravity and its mass. Multiply the coordinates by the mass, add the results for each x and y, then divide by the total mass.

The x-coordinate of the center of gravity is 15/14 a.
The y-coordinate of the center of gravity is 47/42 a.