Attached is a sketch of a sheet rock cart. The cart weighs 79 pounds and I have indicated the location of the centroid. The load on the cart consists of several sheets of material that weigh 1200 pounds. I am trying to determine the pulling force required (F) to tip the cart over (assuming the hinge point A doesn't slide when the cart is pulled). A little background...I am a professional engineer and I am trying to help a client but it has been quite a while since I took physics or statics. I have arrived at an answer of 87 lbs but was hoping for a check from someone with greater knowledge. Thanks for any help.