Trini has finished preschool for the day and her dad has come with a surprise. He has tied a 1.80 m rope to a cart to give her a spin in the cart (during which the rope is parallel to the ground). Together, Trini and the cart have a combined mass of 24 kg. Trini's 2 kg backpack is behind her in the cart. The friction between the wheels of the cart and the ground is negligible.

The rigid beam is supported by the three suspender bars. bars ab and ef are made of aluminum and bar cd is made of steel. if each bar has a cross-sectional area of 450 mm2, determine the maximum value of p if the allowable stress is (σallow)st = 200 mpa for the steel and ( σallow)al = 150 mpa for the aluminum. est = 200 gpa and eal = 70 gpa.

30 points - when can a theory be modified if a new type of technology allows for new observations that raise new questions? a. immediately, while the questions about the theory are being asked b. after new hypotheses related to the theory are tested in experiments c. only after the new observations disprove all parts of the theory d. while scientists begin to think about how the theory could improve

How can waves travel through ground?