Astar has a mass of 1.36 x 1030 kg and is moving in a circular orbit about the center of its galaxy. the radius of the orbit is 2.1 x 104 light-years (1 light-year = 9.5 x 1015 m), and the angular speed of the star is 1.1 x 10-15 rad/s. (a) determine the tangential speed of the star. (b) what is the magnitude of the net force that acts on the star to keep it moving around the center of the galaxy?

Ahot-air balloon takes off from the ground traveling vertically with a constant upward acceleration of magnitude g/4. after time interval δt, a crew member releases a ballast sandbag from the basket attached to the balloon. how many seconds does it take the sandbag to reach the ground? (express your answer in terms of δt)

Consider each of the electric- and magnetic-field orientations given next. in each case, what is the direction of propagation of the wave? a)\vec ein the +xdirection,\vec bin the +ydirection. choose+ x direction- x direction+ y direction- y direction+ z direction- z direction b)\vec ein the -y direction,\vec bin the +x choose+ x direction- x direction+ y direction- y direction+ z direction- z direction c)\vec ein the +z direction,\vec bin the -x direction. choose+ x direction- x direction+ y direction- y direction+ z direction- z direction d)\vec ein the +y direction,\vec bin the -z direction. choose+ x direction- x direction+ y direction- y direction+ z direction- z direction

Based on this activity, is kinetic energy always transformed into potential energy?