有关能量守恒的I push a cart up with a constant force up a slope to
有关能量守恒的
I push a cart up with a constant force up a slope to a height of 1/4 meter.The mass of the cart is 1/4 kg.The cart moves 1/2 meter along the table as I do this.After I let it go,the cart continues up the slope
until it reaches a height of 1/2 meter and then starts back down.What was the magnitude of the force with which I pushed the cart?
45/√5 、