Three persons wants to push a wheel cart in the direction marked x in Fig. The two person push with horizontal forces F1 and F2 as shown in the figure.

(a) Find the magnitude and direction of the force that third person should exert to stop this cart. You can ignore the effects of friction.

(b) If the third person exerts the force found in part (a), the cart accelerates at 200 m/S2 in the (+) x-direction. What is the weight of the cart?