An Airbus A320 jetliner has a takeoff mass of 75000 kg. It reaches its takeoff speed of 82 m/s (180mph) in 35s . For rubber rolling on concrete, Ur=0.02. This is needed for the equation. You can neglect air resistance but not the rubber rolling on concrete. What is the thrust of the engines?

Ababy stroller is a rest on top of a hill which is 10 m high. the stroller and baby have a mass of 20 kg. what is the potential energy of the baby and stroller?

What is the most useful equation for electric power?

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