51: While the hand is applying a force to the cart, is the speed of the cart increasing, decreasing, or staying constant? What evidence from this activity supports your idea ? 52: Do you think the force of the hand was transferred from the hand to the cart during the interaction between them, and then continued to act on it after contact was lost? What evidence supports your idea ? 53: At what moment do you think the force of the hand stopped pushing the cart forwards ? 54: During a contact push/pull interaction, what do you think is transferred from the giver to the receiver: energy, force, both, or neither ? Explain your reasoning