A child of mass 40.0 kg is in a roller coaster car that travels in a loop of radius 8.80 m. At point A the speed of the car is 14.2 m/s, and at point B, the speed is 15.0 m/s. Assume the child is not holding on and does not wear a seat belt.
a. What is the force (in N) of the car seat on the child at point A?
b. What is the force (in N) of the car seat on the child at point B?
c. What minimum speed (in m/s) is required to keep the child in his seat at point A?

Simon is writing a story about an astronaut whose spacecraft has been boarded by space pirates. the astronaut has her lucky penny in her hand behind her back as the space pirates break into the control room. she has just locked the controls so that the ship is accelerating in the direction of the control room’s ceiling. simon wants the astronaut to use the penny to hit a button on the control panel to turn off the lights and escape. the button is located a short distance behind and below the astronaut’s hands. how should simon use the theory of relativity to describe what the astronaut must do in order to hit the button?

Two identical stars with mass m orbit around their center of mass. each orbit is circular and has radius r, so that the two stars are always on opposite sides of the circle. (a) find the gravitational force of one star on the other. (b) find the orbital speed of each star and the period of the orbit. (c) how much energy would be required to separate the two stars to infinity?

Listed below are the measured radiation absorption rates (in w/kg) corresponding to 11 cell phones. use the given data to construct a boxplot and identify the 5-number summary. 1.16 0.85 0.69 0.75 0.95 0.93 1.18 1.17 1.42 0.54 0.57 the 5-number summary is nothing, nothing, nothing, nothing, and nothing, all in w/kg. (use ascending order. type integers or decimals. do not round.)